Animals 173 Humans animal human 173 unclassified drug nonhuman 153 metabolism 131 controlled study 120 chemistry 84 mouse 82 priority journal 81 animal cell 80 Article 76 Mice 70 human cell 68 article 61 protein expression 60 drug effects 58 genetics 57 animal experiment 56 animal model 40 physiology 40 protein function 40 in vivo study 38 cell line 36 female 35 in vitro study 35 Cell Line 33 pathology 31 Female 29