animal cell nonhuman 650 unclassified drug controlled study 533 article 512 Animals 476 priority journal 435 mouse 280 Mice 237 protein expression 193 Humans 190 animal experiment 189 human 188 animal 172 metabolism 143 human cell 141 female 138 rat 135 animal tissue 125 male 124 Article 122 Rats 117 animal model 110 Female 109 antiviral activity 108 Male 102 Cercopithecus aethiops 94 in vitro study 94 Animalia 92 signal transduction 89