Previous studies have found that DNMT3B could be upregulated by TGF-β signaling activation45, and that DNMT3B overexpression accelerates malignant transformation, promotes cancer progression and induces drug resistance in liver cancer, colon cancer and breast cancer, through enhancing DNA hypermethylation-mediated epigenetic suppression of tumor suppressor genes18,19,48–50. Here, DNMT3B is linked to breast cancer.