controlled study human priority journal Humans 823 article 822 human cell 612 female 459 nonhuman 411 Female 390 male 378 Animals 335 adult 323 Male 319 protein expression 281 unclassified drug 275 animal cell 262 Article 245 metabolism 223 Adult 222 mouse 204 Mice 185 Middle Aged 172 clinical article 170 signal transduction 167 animal experiment 154 cell proliferation 147 in vitro study 141 animal 137 aged 136 major clinical study 136