animal experiment nonhuman 240 controlled study 220 Animals 194 priority journal 186 article 172 mouse 160 animal tissue 150 animal cell 124 Mice 122 animal model 114 protein expression 110 male 106 female 102 animal 98 metabolism 90 unclassified drug 86 reverse transcription polymerase chain reaction 84 Male 82 Female 76 messenger RNA 76 Article 70 Humans 64 signal transduction 64 gene expression 62 human 62 RNA, Messenger 60 genetics 56 Reverse Transcriptase Polymerase Chain Reaction 54 Western blotting 50