In this study, no significant differences in the methylation levels of SEPT9 and SDC2 in leukocytes were observed among CRC, Ade, HP and control groups, while either mSEPT9 or mSDC2 level alone in plasma were able to distinguish CRC cases from patients with non-cancerous lesions or healthy subjects. The gene discussed is SEPTIN9; the disease is colorectal carcinoma.