We analyzed methylation of two genes [GSTP1 (glutathione S-transferase P1) and APC (adenomatous polyposis coli)] suggested as potential diagnostic markers for prostate cancer [12–15], of three genes [C1orf114 (chromosome 1 open reading frame 114), GABRE (gamma-aminobutyric acid receptor subunit epsilon), PITX2 (paired-like homeodomain transcription factor 2)] previously associated with prostate cancer prognosis [16–18], and of LINE-1 (long interspersed element-1), a marker of global methylation and a potential diagnostic and prognostic marker for prostate cancer [15–19]. The gene discussed is GSTP1; the disease is prostate cancer.