article controlled study nonhuman unclassified drug priority journal 605 Animals 542 animal cell 408 mouse 239 animal experiment 235 Mice 219 Humans 202 animal tissue 189 human 187 protein expression 184 male 144 female 140 rat 139 enzyme activity 138 Rats 131 human cell 131 Male 129 animal model 127 Female 124 metabolism 116 protein function 110 animal 104 in vitro study 100 antiviral activity 93 messenger RNA 88 Animalia 83