animal cell controlled study nonhuman 388 priority journal unclassified drug Animals 310 article 306 mouse 192 Mice 164 protein expression 138 animal experiment 130 Humans 124 human 112 animal 98 female 96 male 92 animal tissue 90 metabolism 88 rat 86 Rats 82 human cell 82 Article 78 Female 76 animal model 76 Male 72 signal transduction 68 messenger RNA 64 protein function 60 Signal Transduction 56 Cell Line 52