We selected a panel of six tumor suppressor genes that have previously been reported to be frequently methylated in breast tumors, comprising cyclin D2 (CCND2), death-associated protein kinase 1 (DAPK1), glutathione S-transferase P1 (GSTP1), HIN-1, O6-methylguanine-DNA methyltransferase (MGMT) and RASSF1A [22]. The gene discussed is CCND2; the disease is breast neoplasm.