We evaluated the methylation status of 12 putative tumor-suppressor genes (ARHI, RASSF1A, HIN-1, RARβ2, hMLH1, the 14-3-3 σ gene, RIZ1, p16, the E-cadherin gene, RIL, CDH13, and NKD2), LINE1, ER, and PGRB in both culture cell lines and primary cancer tissues. This evidence concerns the gene ESR1 and cancer.