cell count controlled study 64 nonhuman 56 article 50 Animals 48 priority journal 48 animal experiment 36 animal cell 30 female 30 animal model 28 animal tissue 28 mouse 24 Female 22 male 22 unclassified drug 22 Mice 20 animal 20 cell proliferation 20 protein expression 20 rat 20 Male 16 Rats 16 drug effect 16 human 16 Article 14 metabolism 14 Apoptosis 12 apoptosis 12 cytology 12 messenger RNA 12