animal cell controlled study nonhuman 368 priority journal unclassified drug Animals 290 article 286 mouse 177 Mice 150 protein expression 130 animal experiment 122 Humans 116 human 107 female 93 animal 92 male 88 animal tissue 87 metabolism 84 rat 81 Article 78 human cell 77 Rats 75 Female 72 animal model 71 Male 68 signal transduction 64 messenger RNA 59 protein function 55 in vitro study 52 Signal Transduction 51