KLK3 and colorectal cancer: Similar to prostate-specific antigen(PSA) blood test for prostate cancer, a novel serum-based biomarker called colon cancer-specific antigen-2(CCSA-2) was reported [7], which had been detected can be used as a potential marker for colon cancer detection with high sensitivity and specificity, but the value of serum CCSA-2 used in the aspects of prognostic estimation and surveillance after surgery for colorectal cancer was not studied.