GSTP1 and prostate intraepithelial neoplasia: In the course of PCa, the origin of GSTP1 hypermethylation has been traced to late preneoplastic stages like high-grade prostatic intraepithelial neoplasia (Brooks et al, 1998; Yamanaka et al, 2003) and proliferative inflammatory atrophy lesions (Nakayama et al, 2003; Yamanaka et al, 2003).