MGMT and breast cancer: For instance, promoter hypermethylation of the DNA-repair gene O6-methylguanine-DNA methyltransferase (MGMT) is a common event in human neoplasia [13], including glioblastoma multiforme, colorectal or breast cancer or of RASSF1A has been observed in several types of cancer others [36], including HCC, breast, pancreatic or lung cancer, among others.