Animals animal 182 chemistry controlled study nonhuman 165 metabolism 123 unclassified drug 104 priority journal 97 Article 96 human 84 Humans 82 article 82 animal cell 74 animal experiment 54 female 54 genetics 50 mouse 50 animal tissue 49 drug effects 48 Mice 46 human cell 45 male 44 in vitro study 41 Male 40 Female 38 drug effect 38 physiology 38 rat 32 protein expression 31 in vivo study 30