metabolism nonhuman unclassified drug controlled study 298 animal 268 Animals 266 Article 224 priority journal 224 genetics 164 article 156 human 145 animal cell 143 chemistry 139 Humans 136 animal experiment 134 mouse 116 physiology 114 protein expression 108 animal tissue 102 Mice 100 female 87 drug effects 78 protein function 78 Female 71 messenger RNA 71 drug effect 69 gene expression 69 in vitro study 67 enzyme activity 66 male 65