controlled study priority journal unclassified drug nonhuman 763 article 703 Animals 489 animal cell 368 human 275 Humans 263 mouse 243 animal experiment 235 protein expression 231 Mice 210 metabolism 208 Article 192 human cell 188 animal tissue 183 female 170 male 161 animal 147 enzyme activity 142 Female 138 protein function 138 Male 127 animal model 124 rat 121 in vitro study 113 Rats 107 genetics 105 signal transduction 103