controlled study nonhuman 2,094 article 2,084 priority journal 1,701 Animals 1,322 animal experiment 873 human 837 male 817 female 806 animal cell 768 unclassified drug 722 Humans 698 Female 653 Male 637 animal tissue 617 Article 612 mouse 577 metabolism 489 Mice 482 protein expression 470 animal 468 human cell 446 animal model 408 rat 400 enzyme activity 372 adult 337 Rats 321 physiology 263 in vitro study 257 Animalia 244