A number of methylated DNA biomarkers have been found to associate with CRC and precancerous lesions in stool or plasma samples, including SEPT9 (Catherine et al., 2008; Lamb and Dhillon, 2017), SDC2 (Barták et al., 2017; Han et al., 2019), SFRP2 (Barták et al., 2017; Li et al., 2019), and TFPI2 (Glöckner et al., 2009), some of which have been developed into commercial kits for CRC early detection (Potter et al., 2014; Lamb and Dhillon, 2017; Li et al., 2019; Zhao et al., 2019). This evidence concerns the gene SDC2 and colorectal carcinoma.