Article 255 human 238 controlled study 220 Humans 202 metabolism 181 nonhuman 159 male 128 unclassified drug 115 genetics 112 female 107 enzyme linked immunosorbent assay 97 enzyme activity 89 Animals 85 Male 85 adult 85 chemistry 82 animal 80 Female 77 protein expression 73 animal experiment 59 human cell 59 drug effect 55 middle aged 54 gene expression 53 major clinical study 49 Middle Aged 47 animal model 46 mouse 46 animal tissue 45 rat 45