article human unclassified drug Humans 341 controlled study 313 human cell 291 priority journal 261 nonhuman 246 Animals 215 animal cell 133 protein expression 121 Mice 105 mouse 100 Cell Line, Tumor 87 metabolism 85 Cell Line 83 protein function 75 female 71 animal 68 Female 62 in vitro study 59 Male 58 animal experiment 57 chemistry 57 cell proliferation 54 signal transduction 54 messenger RNA 53 drug structure 52 male 52 nucleotide sequence 49