article nonhuman 3,008 priority journal 2,658 controlled study 2,336 Animals 2,255 human 1,259 unclassified drug 1,192 male 1,156 Humans 1,091 female 1,085 animal 1,019 Male 1,013 Female 985 animal experiment 922 animal cell 911 metabolism 855 mouse 675 Mice 661 Argentina 655 animal tissue 646 physiology 591 rat 575 chemistry 563 protein expression 511 Rats 507 Animalia 498 enzyme activity 487 human cell 478 genetics 475 Support, Non-U.S. Gov't 436