nonhuman Article 90 controlled study 75 human 42 Animals 36 unclassified drug 35 animal 34 Humans 32 animal experiment 32 metabolism 32 animal cell 25 mouse 24 in vitro study 21 human cell 19 animal model 18 animal tissue 18 male 18 protein expression 18 rat 18 drug effect 17 female 17 Western blotting 16 chemistry 16 gene expression 16 apoptosis 15 cell membrane 15 membrane protein 15 physiology 14 Mice 13 genetics 13