animal tissue article male nonhuman 120 protein expression controlled study 112 Animals 102 animal experiment 99 priority journal 98 Male 87 animal cell 62 animal model 51 rat 49 mouse 46 Mice 44 Rats 41 female 41 messenger RNA 41 immunohistochemistry 31 Female 25 Western blotting 25 RNA, Messenger 22 Rats, Sprague-Dawley 22 Reverse Transcriptase Polymerase Chain Reaction 22 protein localization 22 human 21 Gene Expression Regulation 20 protein function 20 unclassified drug 20 Immunohistochemistry 19