NDRG4 and colorectal carcinoma: To date, several potential blood-based DNA methylation biomarkers have been identified for CRC detection, including BCAT1, BMP3, C9orf50, CDKN2A, CLIP4, KCNQ5, MLH1, NDRG4, PRIMA1, SDC2, SEPT9, SFRP2, and VIM2,4 (Table 1).