animal cell human 54 human cell in vitro study nonhuman 50 controlled study 46 Animals 42 Humans 42 priority journal 40 mouse 38 Mice 34 animal experiment 34 animal model 30 in vivo study 28 protein expression 28 article 26 male 26 Article 22 animal 22 female 22 unclassified drug 22 metabolism 20 Male 16 cell proliferation 16 Cell Proliferation 14 Mice, Inbred BALB C 14 animal tissue 14 Female 12 signal transduction 12 Antiviral Agents 10