At the same time, the hypermethylation of APC, NEUROG1, RASSF1A, RASSF2A, SDC2, SEPT9, TAC1, and THBD in cfDNA can be detected in patients with early CRC, while the hypermethylation of P16 and TFPI2 in cfDNA is related to the recurrence of CRC (43). The gene discussed is TAC1; the disease is colorectal carcinoma.