KRAS and metastatic malignant neoplasm in the lymph nodes: The lack of detection of common CRC related genes including EGFR, KRAS, BRAF and p53 in tumor together with CEA, CA19-9 and CA24-2 in serum is the limitation of present study.Our future work will focus on the integration of sPD-L1 level in serum and PD-L1 expression on tumor cells in the separate cohorts to future investigate the roles of sPD-L1 on diagnosis for early detection of CRC, prediction for response to the therapy, risk of lymph node metastasis, and prognosis of patients.