Animals animal experiment nonhuman 1,069 priority journal controlled study 924 article 857 animal tissue 563 mouse 513 Male 511 male 508 Mice 497 animal model 475 Female 460 female 453 animal cell 439 animal 317 protein expression 290 rat 285 Rats 279 metabolism 224 Article 210 unclassified drug 199 Humans 186 Rats, Sprague-Dawley 165 Mice, Inbred BALB C 148 physiology 148 human 141 in vivo study 139 enzyme activity 135 signal transduction 128