human Humans 2,888 article 2,403 priority journal 2,032 controlled study 1,748 nonhuman 1,367 Animals 1,281 human cell 1,240 female 1,237 male 1,133 Female 1,095 Male 984 adult 966 metabolism 806 animal 789 unclassified drug 784 Article 660 Adult 656 protein expression 613 physiology 512 genetics 472 animal cell 448 signal transduction 445 mouse 432 chemistry 408 Argentina 405 Mice 402 Middle Aged 394 clinical article 374 major clinical study 349