Animals animal experiment nonhuman controlled study 1,368 article 1,246 priority journal 1,116 animal tissue 792 Male 758 male 758 mouse 744 Mice 710 Female 696 animal model 694 female 686 animal cell 594 animal 546 rat 434 Rats 418 protein expression 384 metabolism 370 Article 358 unclassified drug 312 Humans 278 physiology 258 Animalia 230 human 226 Rats, Sprague-Dawley 216 enzyme activity 214 Mice, Inbred BALB C 208 in vivo study 200