real time reverse transcription polymerase chain reaction 51 Article 49 human 46 Humans 40 controlled study 40 genetics 31 male 30 adult 28 female 28 Male 27 unclassified drug 24 Female 22 middle aged 22 Middle Aged 21 major clinical study 21 gene expression 20 nonhuman 20 human tissue 17 human cell 15 metabolism 15 upregulation 15 coronavirus disease 2019 13 gene expression regulation 13 pathology 13 Gene Expression Regulation, Neoplastic 11 aged 11 blood 11 down regulation 11 protein expression 11 receiver operating characteristic 11