Article animal experiment nonhuman 82 controlled study 80 Animals 60 animal 60 animal tissue 60 mouse 58 gene expression 56 metabolism 54 priority journal 52 male 48 genetics 42 protein expression 40 Mice 38 animal model 38 gene expression regulation 38 unclassified drug 38 Male 34 female 30 messenger RNA 30 human 26 physiology 26 Female 24 animal cell 22 pathology 22 Humans 20 adult 20 cell proliferation 20 gene 18