We investigated the DNA methylation of KGs at CpG sites by MethSurv web-tool with TCGA database and bserved that seven KGs (CEMIP, MMP7, CA4, GUCA2B, ZG16, CLCA4, MS4A12) are significantly methylated at CpG sites (Table 5) that may play the vital role in CRC progression. The gene discussed is CLCA4; the disease is colorectal carcinoma.