controlled study male unclassified drug nonhuman 210 Male 164 priority journal 161 article 154 Animals 144 animal experiment 138 animal cell 112 animal tissue 110 female 101 mouse 100 Article 82 protein expression 76 human 74 animal model 72 animal 70 Female 65 rat 65 metabolism 63 Mice 62 Humans 54 in vitro study 48 Rats 47 human cell 44 adult 42 messenger RNA 41 drug effects 32 in vivo study 32