TAC1 and colorectal carcinoma: In line with the present review, the value of methylation analysis for CRC detection is supported by a systematic review reporting hypermethylation of the APC, neurogenin 1 (NEUROG1), RASSF1A, RASSF2A, SDC2, SEPT9, tachykinin precursor 1 (TAC1), and thrombomodulin (THBD) genes in ctDNA to be detectable in early-stage CRC patients (20).