Animals controlled study nonhuman 1,271 article 1,022 priority journal 873 animal experiment 633 animal cell 571 animal tissue 469 animal 464 Mice 461 mouse 457 male 426 female 421 Male 420 Female 406 unclassified drug 350 metabolism 313 animal model 311 protein expression 302 Article 295 Humans 291 Rats 272 rat 266 human 262 physiology 192 enzyme activity 189 Animalia 171 human cell 154 in vitro study 154 Rats, Sprague-Dawley 143