We noted that terms related to glutathione metabolism (glutathione peroxidase activity and glutathione binding, both q-value < 0.1) were among the most significantly enriched GO terms among the corrected hypermethylated genes in prostate cancer (Supplementary Table S6), and also that Glutathione S-transferase (GST) family members GSTM1, GSTM2 and GSTP1 were among the corrected hypermethylated genes in prostate cancer. The gene discussed is HPGDS; the disease is prostate cancer.