GSTP1 and benign prostatic hyperplasia: Two previously described tissue markers for prostate cancer, AMACR (alpha-methylacyl-CoA racemase) [46] and GSTP1 (Glutathione S-transferase P1) [47] were analyzed regarding the gene expression (AMACR) and promoter methylation (GSTP1), respectively, in tissue samples from TUR-BPH, RP-BPH and RP-PCa in order to additionally characterize the used tissue material.