In any events, due to the complex mechanisms responsible for regulation of DNMT expressions and functions of DNMTs in carcinogenesis, the altered expression and effects of DNMTs should be further investigated in ovarian cancer although their aberrant expressions were found to be because of methylation of their gene promoters in different cancers, such as gliomas and embryonic tissues [42], [43]. This evidence concerns the gene DNMT1 and ovarian cancer.