APC and colorectal cancer: Hypermethylation of cell-free DNA from the blood or stool is considered as a potential non-invasive colorectum cancer biomarker, suggesting several methylation markers that have shown high sensitivity and specificity for screening and early detection (SEPT9, SDC2, MGMT, NDGR4, APC, BMP3, and VIM), prognosis (SFRP, p16, LINE-1, BCAT1/IKZF1, and RASSF1A), and prediction for response to treatment (hMLH1, and Wnt5A) [61].