mSEPT9 (a, c) and mSDC2 (b, d) levels in blood leukocytes (a, b) and plasma (c, d) from CRC, Ade, HP, and other tumor patients as well as control subjects. ns, not significant. *, p < 0.05. **, p < 0.01. ***, p < 0.001. Red lines represent the median methylation levels of SEPT9 and SDC2.