unclassified drug Article 199 controlled study 146 human 121 nonhuman 116 Humans 103 chemistry 93 metabolism 90 male 66 female 59 genetics 58 Animals 52 protein expression 50 animal 47 adult 46 Male 45 Female 44 human cell 43 drug effect 41 animal experiment 39 in vitro study 39 major clinical study 33 biological marker 32 animal tissue 31 middle aged 31 procedures 30 Middle Aged 29 gene expression 29 mouse 29 pathology 29