animal experiment animal model controlled study nonhuman Animals 617 article 601 priority journal 559 mouse 556 animal tissue 448 Mice 432 female 390 animal cell 356 male 345 Female 312 Male 264 protein expression 242 rat 202 animal 201 unclassified drug 187 Article 180 Humans 164 human 162 Rats 161 metabolism 158 Mice, Inbred BALB C 144 in vivo study 139 enzyme activity 129 in vitro study 129 cell proliferation 120 human cell 103