ESR1 and cancer: We have detected aberrant methylation in five cancer-related CpGIs, that is estrogen receptor-α [ESR1 (+244bp)], O6-methylguanine-DNA methyltransferase [MGMT (-463bp)], Wilms' Tumor-1 [WT-1 (-146bp)], Breast Cancer 2 [BRCA2 (+138bp)] and Hermen Antigen [CD44 (+28bp)] (Figure 1).