Animals chemistry animal 504 metabolism 278 article 260 nonhuman 250 human 206 Humans 200 controlled study 192 priority journal 156 unclassified drug 150 Article 140 genetics 116 physiology 112 female 102 animal cell 98 mouse 94 Mice 88 drug effects 88 drug effect 86 Female 82 male 80 Male 76 chemical structure 66 animal experiment 64 human cell 56 isolation and purification 56 amino acid sequence 54 rat 54 animal tissue 52