unclassified drug Article 110 controlled study 87 human 86 Humans 72 nonhuman 66 metabolism 61 male 46 female 43 human cell 43 chemistry 42 genetics 42 protein expression 41 Animals 39 animal 36 Female 34 Male 32 adult 32 in vitro study 32 drug effect 29 animal cell 28 animal experiment 28 mouse 26 gene expression 25 human tissue 25 major clinical study 24 priority journal 23 animal tissue 22 cell proliferation 22 down regulation 21