protein expression nonhuman 561 controlled study 533 priority journal 515 article 511 Animals 446 human 322 Humans 286 animal cell 283 unclassified drug 252 animal experiment 238 mouse 235 Mice 223 female 198 Female 189 animal tissue 188 metabolism 187 human cell 186 protein function 177 male 162 signal transduction 155 animal 146 animal model 141 Article 138 Male 135 messenger RNA 122 cell proliferation 120 enzyme activity 116 rat 109 apoptosis 105