animal cell controlled study nonhuman unclassified drug article 408 Animals 393 priority journal 368 mouse 245 Mice 201 Humans 168 animal experiment 168 protein expression 167 human 165 animal 149 metabolism 128 female 123 human cell 120 Article 118 animal tissue 112 male 112 animal model 99 rat 98 antiviral activity 92 Female 88 Rats 88 Male 86 in vitro study 82 signal transduction 78 Cercopithecus aethiops 75 protein function 73