Animals article controlled study nonhuman 982 priority journal 713 animal experiment 473 animal cell 444 Mice 362 animal tissue 350 mouse 336 Male 316 Female 311 male 307 female 304 unclassified drug 262 Rats 250 animal model 244 protein expression 237 rat 233 Humans 214 human 178 animal 174 Animalia 156 enzyme activity 150 Rats, Sprague-Dawley 131 metabolism 122 human cell 115 drug effect 108 in vitro study 104 signal transduction 98