ZEB1 and breast carcinoma: To further confirm that the inhibition of Ngn3 expression by ZEB1 in breast cancer is correlated with DNA methylation, we conducted bisulfite sequencing PCR (BSP) to evaluate the methylation status of 13 CpG residues in the 243-bp DMR region (-164/+79) of the Ngn3 promoter (Supplementary Figure 5A).