controlled study Article 275 human 199 Humans 167 nonhuman 158 metabolism 123 Animals 110 male 110 animal 105 female 103 human cell 100 unclassified drug 87 genetics 76 adult 75 animal cell 74 animal experiment 72 Female 71 Male 71 chemistry 71 mouse 70 in vitro study 58 animal tissue 55 Mice 54 protein expression 54 major clinical study 52 priority journal 51 drug effect 48 physiology 47 biological marker 46 procedures 46