| 1,25-Dihydroxycholecalciferol 
                  use Calcitriol | 
             
              | 1,25-Dihydroxyvitamin 
                  D3 use Calcitriol | 
             
              | 12-alpha-Hydroxylase 
                  use Steroid 
                  12-alpha-Hydroxylase | 
             
              | 1,2-Benzopyrones 
                  use Coumarins | 
             
              | 1,2-Benzoquinones 
                  use Benzoquinones | 
             
              | 1,2-Cyclic-Inositol-Phosphate 
                  Phosphodiesterase use Glycerophosphoinositol 
                  Inositolphosphodiesterase | 
             
              | 1,2-Dibromoethane 
                  use Ethylene 
                  Dibromide | 
             
              | 1,2-Dimethylhydrazine | 
             
              | 1,2-Dipalmitoylphosphatidylcholine | 
             
              | 1,2-Propanediol 
                  use Propylene 
                  Glycol | 
             
              | 12-R-HETE 
                  use 12-Hydroxy-5,8,10,14-eicosatetraenoic 
                  Acid | 
             
              | 12-S-HETE 
                  use 12-Hydroxy-5,8,10,14-eicosatetraenoic 
                  Acid | 
             
              | 12-S-Hydroxyeicosatetraenoic 
                  Acid use 12-Hydroxy-5,8,10,14-eicosatetraenoic 
                  Acid | 
             
              | 13-cis-Acitretin 
                  use Acitretin | 
             
              | 13-cis-Retinoic 
                  Acid use Isotretinoin | 
             
              | 1,3-Dimethyl-5-aminoadamantane 
                  use Memantine | 
             
              | 1,3-Oxazolidin-2-one 
                  use Oxazolidinones | 
             
              | 14-3-3 
                  Proteins | 
             
              | 1,4,5-InsP3 
                  use Inositol 
                  1,4,5-Trisphosphate | 
             
              | 1,4-alpha-Glucan 
                  Branching Enzyme | 
             
              | 1,4-alpha-Glucosidase, 
                  Exo use Glucan 
                  1,4-alpha-Glucosidase | 
             
              | 1,4-Benzopyrones 
                  use Chromones | 
             
              | 1,4-Benzoquinones 
                  use Benzoquinones | 
             
              | 1,4-Butanolide 
                  use 4-Butyrolactone | 
             
              | 14C 
                  use Carbon 
                  14 | 
             
              | 1,5-Deoxy-1,5-imino-D-Mannitol 
                  use 1-Deoxynojirimycin | 
             
              | 1,5-Diphenylcarbazide 
                  use Diphenylcarbazide | 
             
              | 15-Hydroxy-11 
                  alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid | 
             
              | 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine | 
             
              | 15-Lipoxygenase 
                  use Arachidonate 
                  15-Lipoxygenase | 
             
              | 15-Methylprostaglandin 
                  E2 use Arbaprostil | 
             
              | 15-Methylprostaglandin 
                  F2alpha use Carboprost | 
             
              | 15-Oxoprostaglandin 
                  13-Reductase | 
             
              | 15th 
                  Century History use History, 
                  15th Century | 
             
              | 16,16-Dimethylprostaglandin 
                  E2 | 
             
              | 16S 
                  Ribosomal RNA use RNA, 
                  Ribosomal, 16S | 
             
              | 16th 
                  Century History use History, 
                  16th Century | 
             
              | 17,20-Lyase 
                  use Steroid 
                  17-alpha-Hydroxylase | 
             
              | 17,21-Dimethyl-19-nor-4,9-Pregnadiene-3,20-dione 
                  use Promegestone | 
             
              | 17 
                  alpha-Hydroxylase use Steroid 
                  17-alpha-Hydroxylase | 
             
              | 17-alpha-Hydroxypregnenolone | 
             
              | 17-alpha-Hydroxyprogesterone | 
             
              | 17 
                  beta-Estradiol use Estradiol | 
             
              | 17 
                  beta-Hydroxysteroid Dehydrogenases use 17-Hydroxysteroid 
                  Dehydrogenases | 
             
              | 17-Hydroxycorticosteroids | 
             
              | 17-Hydroxyprogesterone 
                  use 17-alpha-Hydroxyprogesterone | 
             
              | 17-Hydroxysteroid 
                  Dehydrogenases | 
             
              | 17-Ketosteroids | 
             
              | 17-Oxosteroids 
                  use 17-Ketosteroids | 
             
              | 17th 
                  Century History use History, 
                  17th Century | 
             
              | 1,8-Dihydroxy-9-Anthrone 
                  use Anthralin | 
             
              | 18FDG 
                  use Fluorodeoxyglucose 
                  F18 | 
             
              | 18F 
                  Fluorodeoxyglucose use Fluorodeoxyglucose 
                  F18 | 
             
              | 18-Hydrocorticosterone 
                  use 18-Hydroxycorticosterone | 
             
              | 18-Hydroxycorticosterone | 
             
              | 18-Hydroxydesoxycorticosterone | 
             
              | 18S 
                  Ribosomal RNA use RNA, 
                  Ribosomal, 18S | 
             
              | 18th 
                  Century History use History, 
                  18th Century | 
             
              | 19-Iodocholesterol | 
             
              | 19-Norandrostanes 
                  use Estranes | 
             
              | 19-Norandrostenes 
                  use Estrenes | 
             
              | 19-Nortestosterone 
                  use Nandrolone | 
             
              | 19th 
                  Century History use History, 
                  19th Century | 
             
              | 1-Acylglycerol-3-Phosphate 
                  O-Acyltransferase | 
             
              | 1-Acylglycerophosphocholine 
                  Acyltransferase use 1-Acylglycerophosphocholine 
                  O-Acyltransferase | 
             
              | 1-Acylglycerophosphocholine 
                  O-Acyltransferase | 
             
              | 1-Alkyl-2-acetylglycerophosphocholine 
                  Esterase | 
             
              | 1 
                  alpha,25-Dihydroxycholecalciferol use Calcitriol | 
             
              | 1 
                  alpha,25-Dihydroxyvitamin D3 use Calcitriol | 
             
              | 1-Aminocyclopentanecarboxylic 
                  Acid use Cycloleucine | 
             
              | 1-Aminonaphthalene 
                  use 1-Naphthylamine | 
             
              | 1-Butanol | 
             
              | 1-Carboxyglutamic 
                  Acid | 
             
              | 1-Deoxymannojirimycin 
                  use 1-Deoxynojirimycin | 
             
              | 1-Deoxynojirimycin | 
             
              | 1-Heptanol 
                  use Heptanol | 
             
              | 1-Methyl-3-isobutylxanthine | 
             
              | 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine | 
             
              | 1-Methyl-4-phenylpyridinium | 
             
              | 1-Naphthylamine | 
             
              | 1-Naphthylisothiocyanate | 
             
              | 1-Octanol | 
             
              | 1-Oxacephalosporin 
                  use Moxalactam | 
             
              | 1-Phosphatidylinositol 
                  3-Kinase | 
             
              | 1-Phosphatidylinositol 
                  4-Kinase | 
             
              | 1-Phosphatidylinositol 
                  Phosphodiesterase use Phosphatidylinositol 
                  Diacylglycerol-Lyase | 
             
              | 1-Propanol | 
             
              | 1-Pyrroline-5-Carboxylate 
                  Dehydrogenase | 
             
              | 1-Sar-8-Ala 
                  Angiotensin II use Saralasin | 
             
              | 1-Sar-8-Ile 
                  Angiotensin II use 1-Sarcosine-8-Isoleucine 
                  Angiotensin II | 
             
              | 1-Sarcosine-8-Alanine 
                  Angiotensin II use Saralasin | 
             
              | 1-Sarcosine-8-Isoleucine 
                  Angiotensin II | 
             
              | 20,25-Diazacholesterol 
                  use Azacosterol | 
             
              | 20-alpha-Dihydroprogesterone | 
             
              | 20-alpha-Hydroxysteroid 
                  Dehydrogenase | 
             
              | 20-beta-Hydroxysteroid 
                  Dehydrogenase use Cortisone 
                  Reductase | 
             
              | 20-Hydroxyecdysone 
                  use Ecdysterone | 
             
              | 20-Hydroxysteroid 
                  Dehydrogenases | 
             
              | 20th 
                  Century History use History, 
                  20th Century | 
             
              | 21-Hydroxyprogesterone 
                  use Desoxycorticosterone | 
             
              | 21st 
                  Century History use History, 
                  21st Century | 
             
              | 2,2-Bipyridine 
                  use 2,2'-Dipyridyl | 
             
              | 2,2'-Dipyridyl | 
             
              | 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine | 
             
              | 2,3-Bisphosphoglycerate 
                  use 2,3-Diphosphoglycerate | 
             
              | 2,3-Butanedione 
                  use Diacetyl | 
             
              | 2',3'-Cyclic-Nucleotide 
                  Phosphodiesterases | 
             
              | 2',3'-Didehydro-3'-deoxythymidine 
                  use Stavudine | 
             
              | 2',3'-Dideoxy-3'-thiacytidine 
                  use Lamivudine | 
             
              | 2',3'-Dideoxyadenosine 
                  use Dideoxyadenosine | 
             
              | 2',3'-Dideoxycytidine 
                  use Zalcitabine | 
             
              | 2',3'-Dideoxyinosine 
                  use Didanosine | 
             
              | 2',3'-Dideoxynucleosides 
                  use Dideoxynucleosides | 
             
              | 2,3-Diketogulonic 
                  Acid | 
             
              | 2,3-Diphosphoglycerate | 
             
              | 2,3-Diphosphoglyceric 
                  Acid use 2,3-Diphosphoglycerate | 
             
              | 2,3-DPG 
                  use 2,3-Diphosphoglycerate | 
             
              | 23S 
                  Ribosomal RNA use RNA, 
                  Ribosomal, 23S | 
             
              | 24,25-Dihydroxycholecalciferol 
                  use 24,25-Dihydroxyvitamin 
                  D 3 | 
             
              | 24,25-Dihydroxyvitamin 
                  D 3 | 
             
              | 2,4,5-Trichlorophenoxyacetic 
                  Acid | 
             
              | 2,4,5-T 
                  use 2,4,5-Trichlorophenoxyacetic 
                  Acid | 
             
              | 2,4,6-Trinitro-1-chlorobenzene 
                  use Picryl 
                  Chloride | 
             
              | 24-Dehydrocholesterol 
                  use Desmosterol | 
             
              | 2,4-Dichlorophenoxyacetic 
                  Acid | 
             
              | 2,4-Dinitrophenol | 
             
              | 2,4-DNP 
                  use 2,4-Dinitrophenol | 
             
              | 2,4-D 
                  use 2,4-Dichlorophenoxyacetic 
                  Acid | 
             
              | 2-5A 
                  Synthetase use 2',5'-Oligoadenylate 
                  Synthetase | 
             
              | 2,5-Dihydroxybenzoic 
                  Acids use Gentisates | 
             
              | 2,5-Dimethoxy-4-Methylamphetamine | 
             
              | 2,5-Furandiones 
                  use Maleic 
                  Anhydrides | 
             
              | 25-Hydroxycholecalciferol 
                  1-Hydroxylase use 25-Hydroxyvitamin 
                  D3 1-alpha-Hydroxylase | 
             
              | 25-Hydroxycholecalciferol 
                  use Calcifediol | 
             
              | 25-Hydroxyergocalciferol 
                  use 25-Hydroxyvitamin 
                  D 2 | 
             
              | 25-Hydroxyvitamin 
                  D 2 | 
             
              | 25-Hydroxyvitamin 
                  D3 1-alpha-Hydroxylase | 
             
              | 25-Hydroxyvitamin 
                  D 3 use Calcifediol | 
             
              | 2',5'-Oligoadenylate 
                  Polymerase use 2',5'-Oligoadenylate 
                  Synthetase | 
             
              | 2',5'-Oligoadenylate 
                  Synthetase | 
             
              | 2,6-Dichloroindophenol | 
             
              | 2,6-Dichlorophenolindophenol 
                  use 2,6-Dichloroindophenol | 
             
              | 28S 
                  Ribosomal RNA use RNA, 
                  Ribosomal, 28S | 
             
              | 2-Acetamidofluorene 
                  use 2-Acetylaminofluorene | 
             
              | 2-Acetohydroxy-3-Ketoacid 
                  Isomeroreductase use 2-Acetolactate 
                  Mutase | 
             
              | 2-Acetolactate 
                  Mutase | 
             
              | 2-Acetylaminofluorene | 
             
              | 2-Alanyl-Leucine 
                  Enkephalin use Enkephalin, 
                  Leucine-2-Alanine | 
             
              | 2-Amino-4-Mercaptobutyric 
                  acid use Homocysteine | 
             
              | 2-Amino-5-phosphonopentanoic 
                  Acid use 2-Amino-5-phosphonovalerate | 
             
              | 2-Amino-5-phosphonovalerate | 
             
              | 2-Amino-5-phosphonovaleric 
                  Acid use 2-Amino-5-phosphonovalerate | 
             
              | 2-Amino-6-(1,2,3-trihydroxypropyl)-4(3H)-pteridinone 
                  use Neopterin | 
             
              | 2-Aminoadipate 
                  Transaminase | 
             
              | 2-Aminoadipic 
                  Acid | 
             
              | 2-Aminoethanol 
                  use Ethanolamine | 
             
              | 2-Aminoethylisothiuronium 
                  Bromide use beta-Aminoethyl 
                  Isothiourea | 
             
              | 2-Aminoethylphosphonic 
                  Acid use Aminoethylphosphonic 
                  Acid | 
             
              | 2-Aminonaphthalene 
                  use 2-Naphthylamine | 
             
              | 2-Aminopurine | 
             
              | 2-Bromoergocryptine 
                  use Bromocriptine | 
             
              | 2-Butenedioic 
                  Acid use Fumaricum 
                  Acidum | 
             
              | 2-Butenoic 
                  Acids use Crotonic 
                  Acids | 
             
              | 2-Chlorethanol 
                  use Ethylene 
                  Chlorohydrin | 
             
              | 2-Chloro-2'-deoxyadenosine 
                  use Cladribine | 
             
              | 2-Chloroacetophenone 
                  use omega-Chloroacetophenone | 
             
              | 2-Chloroadenosine | 
             
              | 2-Chlorodeoxyadenosine 
                  use Cladribine | 
             
              | 2-Chloroethyl 
                  Alcohol use Ethylene 
                  Chlorohydrin | 
             
              | 2-Dehydro-3-Deoxyphosphoheptonate 
                  Aldolase use 3-Deoxy-7-Phosphoheptulonate 
                  Synthase | 
             
              | 2'-Deoxycoformycin 
                  use Pentostatin | 
             
              | 2-Fluoro-2-deoxy-D-Glucose 
                  use Fluorodeoxyglucose 
                  F18 | 
             
              | 2-Fluoro-2-deoxyglucose 
                  use Fluorodeoxyglucose 
                  F18 | 
             
              | 2H-Benzo(a)quinolizin-2-ol, 
                  2-Ethyl-1,3,4,6,7,11b-hexahydro-3-isobutyl-9,10-dimethoxy- | 
             
              | 2-Hexanone 
                  use Methyl 
                  n-Butyl Ketone | 
             
              | 2-Hydroxy-5-nitrobenzyl 
                  Bromide | 
             
              | 2-Hydroxyphenethylamine | 
             
              | 2-Isopropylmalate 
                  Synthase | 
             
              | 2-Mercaptoethanesulfonate 
                  use Mesna | 
             
              | 2-Methyl-4-chlorophenoxyacetic 
                  Acid | 
             
              | 2-Naphthylamine | 
             
              | 2-Nicotinamidoethyl 
                  Nitrate use Nicorandil | 
             
              | 2-Oxo 
                  Acid Carboxy-Lyase use Pyruvate 
                  Decarboxylase | 
             
              | 2-Oxoisovalerate 
                  Dehydrogenase (Acylating) | 
             
              | 2-Oxoisovalerate 
                  Dehydrogenase (Lipoamide) use 3-Methyl-2-Oxobutanoate 
                  Dehydrogenase (Lipoamide) | 
             
              | 2-PAM 
                  Compounds use Pralidoxime 
                  Compounds | 
             
              | 2-Phenylethanolamine 
                  use 2-Hydroxyphenethylamine | 
             
              | 2-Propanol | 
             
              | 2-Pyridinylmethylsulfinylbenzimidazoles | 
             
              | 3,3',5'-Triiodothyronine 
                  use Triiodothyronine, 
                  Reverse | 
             
              | 3,3'-Diaminobenzidine | 
             
              | 3,3'-Dichlorobenzidine | 
             
              | 3,4-Benzopyrene 
                  use Benzo(a)pyrene | 
             
              | 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, 
                  (trans)-Isomer | 
             
              | 3,4-Dihydroxyphenylacetic 
                  Acid | 
             
              | 3,4-Dihydroxyphenylserine 
                  use Droxidopa | 
             
              | 3,4-Methylenedioxyamphetamine | 
             
              | 3',5'-Cyclic 
                  AMP 5'-Nucleotidohydrolase use 3',5'-Cyclic-AMP 
                  Phosphodiesterases | 
             
              | 3',5'-Cyclic-AMP 
                  Phosphodiesterases | 
             
              | 3',5'-Cyclic 
                  GMP 5'-Nucleotidohydrolase use 3',5'-Cyclic-GMP 
                  Phosphodiesterases | 
             
              | 3',5'-Cyclic-GMP 
                  Phosphodiesterases | 
             
              | 3',5'-Cyclic-Nucleotide 
                  Phosphodiesterase use 3',5'-Cyclic-AMP 
                  Phosphodiesterases | 
             
              | 3-alpha-Hydroxysteroid 
                  Dehydrogenase (B-Specific) | 
             
              | 3-Aminopropionic 
                  Acid use beta-Alanine | 
             
              | 3-Aminopropylene 
                  use Allylamine | 
             
              | 3 
                  beta-Hydroxy-delta-5-Steroid Dehydrogenase use Progesterone 
                  Reductase | 
             
              | 3-beta-Hydroxysteroid 
                  Dehydrogenase use 3-Hydroxysteroid 
                  Dehydrogenases | 
             
              | 3-Deazauridine | 
             
              | 3-Deoxy-7-Phosphoheptulonate 
                  Synthase | 
             
              | 3-Deoxyarabinoheptulosonate-7-Phosphate 
                  Synthetase use 3-Deoxy-7-Phosphoheptulonate 
                  Synthase | 
             
              | 3' 
                  End Processing, RNA use RNA 
                  3' End Processing | 
             
              | 3' 
                  Flanking Region | 
             
              | 3-Hydroxy-3-methylglutaric 
                  Acid use Meglutol | 
             
              | 3-Hydroxyacyl 
                  CoA Dehydrogenases | 
             
              | 3-Hydroxyacyl 
                  CoA Hydrolyases use Enoyl-CoA 
                  Hydratase | 
             
              | 3-Hydroxyacyl 
                  Dehydratases use Enoyl-CoA 
                  Hydratase | 
             
              | 3-Hydroxyanthranilate 
                  3,4-Dioxygenase | 
             
              | 3-Hydroxyanthranilic 
                  Acid | 
             
              | 3-Hydroxybutyrate 
                  use 3-Hydroxybutyric 
                  Acid | 
             
              | 3-Hydroxybutyric 
                  Acid | 
             
              | 3-Hydroxysteroid 
                  Dehydrogenases | 
             
              | 3-Iodobenzylguanidine | 
             
              | 3-Isobutyl-1-methylxanthine 
                  use 1-Methyl-3-isobutylxanthine | 
             
              | 3-Isoleucyl 
                  Vasopressin use Vasotocin | 
             
              | 3-Isopropylmalate 
                  Dehydrogenase | 
             
              | 3-Keto-5-alpha-Steroid 
                  delta-4-Dehydrogenase use Testosterone 
                  5-alpha-Reductase | 
             
              | 3-Ketoacyl 
                  CoA Thiolase use Acetyl-CoA 
                  C-Acyltransferase | 
             
              | 3-Ketosteroid 
                  Isomerases use Steroid 
                  Isomerases | 
             
              | 3-Ketothiolase 
                  use Acetyl-CoA 
                  C-Acyltransferase | 
             
              | 3-Mercaptopropanoic 
                  Acid use 3-Mercaptopropionic 
                  Acid | 
             
              | 3-Mercaptopropionic 
                  Acid | 
             
              | 3-Methoxy-4-hydroxyphenylethanol | 
             
              | 3-Methyl-2-Oxobutanoate 
                  Dehydrogenase (Lipoamide) | 
             
              | 3-Methylindole 
                  use Skatole | 
             
              | 3-O-Methyl-D-Glucose 
                  use 3-O-Methylglucose | 
             
              | 3-O-Methylglucose | 
             
              | 3-Oxoacyl-(Acyl-Carrier-Protein) 
                  Synthase | 
             
              | 3-Oxosteroid 
                  Isomerases use Steroid 
                  Isomerases | 
             
              | 3-Phosphoglyceraldehyde 
                  use Glyceraldehyde 
                  3-Phosphate | 
             
              | 3-Phosphoshikimate 
                  1-Carboxyvinyltransferase | 
             
              | 3-Pyridinecarboxylic 
                  acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, 
                  Methyl ester | 
             
              | 3-Sulfoalanine 
                  use Cysteic 
                  Acid | 
             
              | 3T3 
                  Cells | 
             
              | 3T3-L1 
                  Cells | 
             
              | 3TC 
                  use Lamivudine | 
             
              | 3' 
                  Untranslated Regions | 
             
              | 3'UTR 
                  use 3' 
                  Untranslated Regions | 
             
              | 4-1BB 
                  Ligand | 
             
              | 4-1BB 
                  Receptors use Antigens, 
                  CD137 | 
             
              | 4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone | 
             
              | 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic 
                  Acid | 
             
              | 4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine | 
             
              | 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic 
                  Acid | 
             
              | 4-Aminobenzoic 
                  Acid | 
             
              | 4-Aminobutyrate 
                  Transaminase | 
             
              | 4-Aminobutyric 
                  Acid use gamma-Aminobutyric 
                  Acid | 
             
              | 4-Aminohippuric 
                  Acid use p-Aminohippuric 
                  Acid | 
             
              | 4-Aminopyridine | 
             
              | 4-Aminosalicylic 
                  Acid use p-Aminosalicylic 
                  Acid | 
             
              | 4-Butyrolactone | 
             
              | 4-Chloro-7-nitrobenzofurazan | 
             
              | 4-Chloromercuribenzenesulfonate | 
             
              | 4-Demethoxydaunorubicin 
                  use Idarubicin | 
             
              | 4'-Epiadriamycin 
                  use Epirubicin | 
             
              | 4'-Epidoxorubicin 
                  use Epirubicin | 
             
              | 4-Homosulfanilamide 
                  use Mafenide | 
             
              | 4-HPR 
                  use Fenretinide | 
             
              | 4-Hydroxyaminoquinoline-1-oxide | 
             
              | 4-Hydroxyaminoquinoline-N-oxide 
                  use 4-Hydroxyaminoquinoline-1-oxide | 
             
              | 4-Hydroxybenzoate-3-Monooxygenase | 
             
              | 4-Hydroxybenzoic 
                  Acids use Parabens | 
             
              | 4-Hydroxybutyrate 
                  Sodium use Sodium 
                  Oxybate | 
             
              | 4-Hydroxybutyric 
                  Acid Lactone use 4-Butyrolactone | 
             
              | 4-Hydroxycoumarins | 
             
              | 4 
                  Hydroxyphenylpyruvate Dioxygenase Deficiency Disease 
                  use Tyrosinemias | 
             
              | 4-Hydroxyphenylpyruvate 
                  Dioxygenase | 
             
              | 4-Nitrophenol-2-Hydroxylase 
                  use Cytochrome 
                  P-450 CYP2E1 | 
             
              | 4-Nitrophenylphosphatase | 
             
              | 4-Nitroquinoline-1-oxide | 
             
              | 4-Nitroquinoline-N-oxide 
                  use 4-Nitroquinoline-1-oxide | 
             
              | 4-Quinolones | 
             
              | 5,10-Methylenetetrahydrofolate 
                  Reductase (FADH2) | 
             
              | 5,10-Methylenetetrahydrofolate-Reductase 
                  (NADH) use Methylenetetrahydrofolate 
                  Dehydrogenase (NAD+) | 
             
              | 5,12-DiHETE 
                  use Leukotriene 
                  B4 | 
             
              | 5,12-HETE 
                  use Leukotriene 
                  B4 | 
             
              | 5,5'-Dithiobis(2-nitrobenzoic 
                  Acid) use Dithionitrobenzoic 
                  Acid | 
             
              | 5,6-Benzoflavone 
                  use beta-Naphthoflavone | 
             
              | 5,6-Dihydroxytryptamine | 
             
              | 5,7-Dihydroxytryptamine | 
             
              | 5,8,11,14,17-Eicosapentaenoic 
                  Acid use Eicosapentaenoic 
                  Acid | 
             
              | 5,8,11,14-Eicosatetraynoic 
                  Acid | 
             
              | 5.8S 
                  Ribosomal RNA use RNA, 
                  Ribosomal, 5.8S | 
             
              | 5-alpha-Dihydroprogesterone | 
             
              | 5 
                  alpha-Dihydrotestosterone use Dihydrotestosterone | 
             
              | 5-alpha-Reductase, 
                  Testosterone use Testosterone 
                  5-alpha-Reductase | 
             
              | 5-Amino-3-((5-nitro-2-furyl)vinyl)-1,2,4-oxadiazole | 
             
              | 5-Aminolevulinate 
                  Synthetase | 
             
              | 5-Aminosalicylate 
                  use Mesalamine | 
             
              | 5'-AMP 
                  Nucleotidase use 5'-Nucleotidase | 
             
              | 5' 
                  Flanking Region | 
             
              | 5-Fluorocytosine 
                  use Flucytosine | 
             
              | 5'-Guanylic 
                  Acid | 
             
              | 5-HT 
                  Agonists use Serotonin 
                  Agonists | 
             
              | 5-HT 
                  Antagonists use Serotonin 
                  Antagonists | 
             
              | 5-HTP 
                  use 5-Hydroxytryptophan | 
             
              | 5-HT 
                  Receptors use Receptors, 
                  Serotonin | 
             
              | 5-HT 
                  use Serotonin | 
             
              | 5-HT 
                  Uptake Inhibitors use Serotonin 
                  Uptake Inhibitors | 
             
              | 5-Hydroxytryptamine 
                  Agonists use Serotonin 
                  Agonists | 
             
              | 5-Hydroxytryptamine 
                  Antagonists use Serotonin 
                  Antagonists | 
             
              | 5-Hydroxytryptamine 
                  Receptors use Receptors, 
                  Serotonin | 
             
              | 5-Hydroxytryptamine 
                  use Serotonin | 
             
              | 5-Hydroxytryptamine 
                  Uptake Inhibitors use Serotonin 
                  Uptake Inhibitors | 
             
              | 5-Hydroxytryptophan | 
             
              | 5-Iodo-2'-deoxyuridine 
                  use Idoxuridine | 
             
              | 5-Leucine-2-Alanine 
                  Enkephalin use Enkephalin, 
                  Leucine-2-Alanine | 
             
              | 5-Lipoxygenase 
                  use Arachidonate 
                  5-Lipoxygenase | 
             
              | 5-Methoxytryptamine | 
             
              | 5-Methylcytosine | 
             
              | 5-Methyltetrahydrofolate-Homocysteine 
                  S-Methyltransferase | 
             
              | 5'-N-Ethylcarboxamidoadenosine 
                  use Adenosine-5'-(N-ethylcarboxamide) | 
             
              | 5'-Nucleotidase | 
             
              | 5-Oxoproline 
                  use Pyrrolidonecarboxylic 
                  Acid | 
             
              | 5-Oxoprolyl-Peptidase 
                  use Pyroglutamyl-Peptidase 
                  I | 
             
              | 5p 
                  Deletion Syndrome use Cri-du-Chat 
                  Syndrome | 
             
              | 5S 
                  Ribosomal RNA use RNA, 
                  Ribosomal, 5S | 
             
              | 5' 
                  Untranslated Regions | 
             
              | 5'UTR 
                  use 5' 
                  Untranslated Regions | 
             
              | 6-Aminocaproic 
                  Acid | 
             
              | 6-Aminohexanoic 
                  Acid use 6-Aminocaproic 
                  Acid | 
             
              | 6-Aminonicotinamide | 
             
              | 6-Cyano-7-nitroquinoxaline-2,3-dione | 
             
              | 6-Hydroxydopamine 
                  use Oxidopamine | 
             
              | 6-Iodomethylnorcholesterol 
                  use Adosterol | 
             
              | 6-Keto-PGF1 
                  alpha use 6-Ketoprostaglandin 
                  F1 alpha | 
             
              | 6-Ketoprostaglandin 
                  F1 alpha | 
             
              | 6-Mercaptopurine 
                  Riboside use Thioinosine | 
             
              | 6-Mercaptopurine | 
             
              | 6-Methylmercaptopurine 
                  Riboside use Methylthioinosine | 
             
              | 6-OHDA 
                  use Oxidopamine | 
             
              | 6-Oxo-PGF1 
                  alpha use 6-Ketoprostaglandin 
                  F1 alpha | 
             
              | 6-Oxoprostaglandin 
                  F1 alpha use 6-Ketoprostaglandin 
                  F1 alpha | 
             
              | 6-Phosphofructo-2-kinase-fructose-2,6-bisphosphatase 
                  use Phosphofructokinase-2 | 
             
              | 6-Phosphofructo-2-Kinase 
                  use Phosphofructokinase-2 | 
             
              | 6-Phosphofructokinase, 
                  Liver Type use Phosphofructokinase-1, 
                  Liver Type | 
             
              | 6-Phosphofructokinase, 
                  Muscle Type use Phosphofructokinase-1, 
                  Muscle Type | 
             
              | 6-Phosphofructokinase, 
                  Platelet Type use Phosphofructokinase-1, 
                  Type C | 
             
              | 6-Phosphofructokinase 
                  use Phosphofructokinase-1 | 
             
              | 6-Phytase | 
             
              | 6-Thioguanine 
                  use Thioguanine | 
             
              | 7,12-Dimethylbenzanthracene 
                  use 9,10-Dimethyl-1,2-benzanthracene | 
             
              | 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 
                  9,10-oxide | 
             
              | 7,8-Dihydroxy-9,10-Epoxy-7,8,9,10-Tetrahydrobenzo(a)pyrene 
                  use 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 
                  9,10-oxide | 
             
              | 7-Alkoxycoumarin 
                  O-Dealkylase | 
             
              | 7-Deazaadenosine 
                  use Tubercidin | 
             
              | 7-Ethoxycoumarin 
                  O-Dealkylase use 7-Alkoxycoumarin 
                  O-Dealkylase | 
             
              | 7-Ethoxycoumarin 
                  O-Deethylase use 7-Alkoxycoumarin 
                  O-Dealkylase | 
             
              | 7-Hydroxycoumarins 
                  use Umbelliferones | 
             
              | 8,11,14-Eicosatrienoic 
                  Acid | 
             
              | 8-Bromo-CAMP 
                  use 8-Bromo 
                  Cyclic Adenosine Monophosphate | 
             
              | 8-Bromo 
                  Cyclic Adenosine Monophosphate | 
             
              | 8-Hydroxy-2-(di-n-propylamino)tetralin | 
             
              | 8-Methoxypsoralen 
                  use Methoxsalen | 
             
              | 8-OH-DPAT 
                  use 8-Hydroxy-2-(di-n-propylamino)tetralin | 
             
              | 8-Quinolinol 
                  use Oxyquinoline | 
             
              | 11-beta-Hydroxysteroid 
                  Dehydrogenases | 
             
              | 11-beta-Hydroxysteroid 
                  Dehydrogenase Type 1 | 
             
              | 11-beta-Hydroxysteroid 
                  Dehydrogenase Type 2 | 
             
              | 11-Dehydroprostaglandin 
                  F2alpha use Prostaglandin 
                  D2 | 
             
              | 11-Deoxycortisol 
                  use Cortodoxone | 
             
              | 11-Desoxycortisone 
                  use Cortodoxone | 
             
              | 11-Hydroxycorticosteroids | 
             
              | 11q 
                  Deletion Disorder use Jacobsen 
                  Distal 11q Deletion Syndrome | 
             
              | 12-HETE 
                  use 12-Hydroxy-5,8,10,14-eicosatetraenoic 
                  Acid | 
             
              | 12-Hydroxy-5,8,10,14-eicosatetraenoic 
                  Acid | 
             
              | 12-Lipoxygenase 
                  use Arachidonate 
                  12-Lipoxygenase | 
             
              | 12-Methoxyibogamine 
                  use Ibogaine |