Loss of GSTP1 expression by promoter hypermethylation is a major event in prostate cancer in which GSTP1 is found hypermethylated in 73% of cases with a sensitivity of 73%, a specificity of 100%, a positive predictive value (PPV) of 100% and a negative predictive value (NPV) of 78% [83]. This evidence concerns the gene GSTP1 and prostate carcinoma.