gene expression level Article 21 controlled study 21 human 19 Humans 13 genetics 13 adult 11 female 10 male 10 nonhuman 10 unclassified drug 9 human tissue 8 Female 7 Male 7 down regulation 7 gene expression 7 human cell 7 metabolism 7 middle aged 6 pathology 6 receiver operating characteristic 6 sensitivity and specificity 6 tumor marker 6 Biomarkers, Tumor 5 Gene Expression Regulation, Neoplastic 5 Middle Aged 5 cell proliferation 5 diagnostic value 5 gene expression regulation 5 major clinical study 5