Reverse Transcriptase Polymerase Chain Reaction 52 gene expression Animals 46 controlled study 46 nonhuman 44 article 42 priority journal 42 animal cell 34 reverse transcription polymerase chain reaction 30 Mice 28 Male 26 mouse 26 protein expression 24 Humans 22 RNA, Messenger 22 animal experiment 22 female 22 Blotting, Western 20 human 20 male 20 messenger RNA 20 Female 18 Immunohistochemistry 18 RNA 18 animal tissue 18 nucleotide sequence 18 cell proliferation 16 human cell 16 metabolism 16 unclassified drug 16