Animals controlled study priority journal nonhuman 1,795 article 1,527 animal cell 925 animal experiment 924 Mice 750 mouse 731 animal tissue 710 male 609 Male 606 Female 592 female 583 animal 529 protein expression 503 unclassified drug 489 animal model 470 Rats 435 rat 416 Humans 405 metabolism 383 human 335 Article 318 enzyme activity 256 signal transduction 255 physiology 235 Rats, Sprague-Dawley 228 in vitro study 217 human cell 214