It was suggested that one-third of all patho-physiological mutations occur at methylated CpG sites, examples of this type of mutation and associated diseases were found in DNMT3A (acute myeloid leukaemia), DNMT1 (colorectal cancer), DNMT3B (ICF), p53 (colorectal, breast and ovarian cancers), and BRCA1 (breast and ovarian cancers) (reviewed in [173]). This evidence concerns the gene BRCA1 and ovarian cancer.