controlled study human nonhuman Humans 534 Animals 496 article 448 priority journal 428 human cell 402 animal cell 384 mouse 316 unclassified drug 296 Mice 262 animal 252 animal experiment 240 protein expression 230 Article 222 metabolism 212 female 200 animal model 178 male 174 Female 166 animal tissue 140 genetics 138 Male 128 in vitro study 122 cell proliferation 104 signal transduction 104 in vivo study 102 Cell Line 100 chemistry 100