controlled study human 644 human cell priority journal article 504 Humans 480 nonhuman 266 Animals 226 protein expression 226 unclassified drug 202 animal cell 196 female 168 Female 150 signal transduction 144 metabolism 136 mouse 136 Mice 132 cell proliferation 132 Article 128 male 120 in vitro study 108 Cell Line 106 Cell Line, Tumor 106 Male 106 protein function 102 animal experiment 98 apoptosis 96 Western blotting 86 enzyme activity 80 Signal Transduction 78