Since, studies have identified de-novo methyltransferases, DNMT3b, over-expressed in breast tumors [15], indicating an involvement of epigenetic modifications in oncogenesis, breast cancer susceptibility genes, identified under the categories of DNA damage response (DDR) and apoptosis related genes could be a major target of epigenetic inactivation in sporadic breast cancers. The gene discussed is DNMT3B; the disease is breast carcinoma.