Among the earlier genes whose methylation in ctDNA has been described in CRC includes SEPT9, for which several groups have shown that postoperative ctDNA-positivity for SEPT9 carries high specificity for predicting recurrent CRC [44,45,46,47,48] while conferring a median lead time of 8 months prior to radiographic detection of recurrence in resected CRC patients [27]. Here, SEPTIN9 is linked to colorectal carcinoma.