GSTP1 and prostate carcinoma: While a large number of differentially methylated genes were identified, in prostate cancer the only commercially available methylation-based test is ‘ConfirmMDx’ (MDxHealth, Inc, Irvine, CA), which relies on the methylation status of three genes (GSTP1, APC and RASSF1) from biopsy tissues to avoid unnecessary repeat biopsies [18].