Flavonoid luteolin has been found to promote cell cycle arrest and death in HeLa cells through reducing DNMT1 expression [25], and luteolin also inhibits intracellular methylation activity of breast cancer cells [26], flavonoid nobiletin enhances the efficacy of chemotherapy through targeting colorectal cancer stem cells [27], and flavonoid nobiletin attenuates hepatocyte growth factor (HGF)-induced liver cancer cells metastasis [28]. This evidence concerns the gene DNMT1 and breast cancer.