First, although we retrieved current online databases including PubMed, Cochrane, CNKI, CBM, and Wan-Fang Database in China without language restrictions, all the included articles relating to CKI combined with chemotherapeutic drugs versus chemotherapeutic drugs alone for advanced colon cancer patients were only found in China, which indicated that publication bias might exist across studies. This evidence concerns the gene CHKA and malignant colon neoplasm.