GSTP1 and prostatitis: studied DNA methylation of a set of genes (GSTP1, RASSF1A, RARB, CD44, EDNRB, CDH1, ANXA2, and CAV1) that were previously implicated in prostate tumorigenesis in AA patient samples and reported that GSTP1, RASSF1A, and RARB were hypermethylated and CDH1, EDNRB, and CD44 were hypomethylated in tumor samples (24).