GSTP1 and prostate cancer: A July 31, 2018 PubMed search for “prostate cancer etiology and biomarkers and DNA methylated genes and blood” identified 11 articles describing DNA methylated genes in PCa including promoter methylation of the GSTP1 (glutathione S-transferase P1) gene which is the most common methylated gene reported thus far for PCa, appearing earlier and more frequently than other gene defects that arise during PCa development [31,34].