controlled study nonhuman protein function article 245 priority journal 243 Animals 222 animal cell 179 protein expression 168 unclassified drug 150 mouse 144 animal experiment 121 Mice 113 metabolism 104 animal tissue 97 human 94 Humans 85 protein analysis 85 animal 82 male 81 animal model 75 Article 74 female 70 genetics 70 rat 68 Female 66 human cell 59 Rats 58 protein localization 58 Male 55 enzyme activity 55