The overexpression of DNMT3B isoforms has been reported in several types of cancer cells; for example, DNMT3B3 and DNMT3B4 in gastric cancer [33], DNMT3B4 in the liver and clear cells renal cancers [33,34,35], DNMT3B7 in breast cancer [36,37], and ΔDNMT3B4 in lung cancer [20]; however, the expression patterns and consequences of DNMT3B isoforms’ overexpression in EOC are still unknown. Here, DNMT3B is linked to breast cancer.