human metabolism nonhuman Humans 320 Animals 274 animal 274 controlled study 212 priority journal 194 animal cell 156 unclassified drug 152 mouse 150 genetics 148 Article 134 Mice 126 article 124 human cell 114 chemistry 108 protein expression 108 animal experiment 104 physiology 100 female 88 pathology 80 signal transduction 80 animal model 76 Female 72 protein function 70 gene expression regulation 64 in vitro study 64 drug effects 62 in vivo study 62