Article 334 human 300 controlled study 273 Humans 220 nonhuman 167 male 150 unclassified drug 141 enzyme linked immunosorbent assay 140 female 136 human cell 122 metabolism 121 adult 98 Animals 97 animal 95 Male 92 Female 88 animal experiment 84 genetics 83 chemistry 82 in vitro study 79 mouse 74 protein expression 74 animal model 64 middle aged 64 pathology 64 drug effect 63 major clinical study 62 cell proliferation 61 gene expression 61 Western blotting 60