animal cell article nonhuman 420 protein expression Animals 364 controlled study 364 priority journal 335 Mice 234 mouse 232 animal experiment 177 animal tissue 140 unclassified drug 136 female 135 Female 126 Humans 126 animal model 119 human 116 male 111 messenger RNA 101 rat 101 human cell 92 protein function 90 Male 87 signal transduction 87 Rats 84 animal 84 cell proliferation 83 metabolism 75 Mice, Inbred BALB C 74 Animalia 72