With the in-depth study of the immune checkpoint mechanism, treatment targeting CTLA-4, PD-1/PD-L1, and other immune checkpoints has demonstrated efficacy in the treatment of a range of malignancies, including urothelial carcinoma(UC) [2], renal cell carcinoma(RCC) [3], melanoma [4], non-small-cell lung cancer(NSCLC) [5], colorectal carcinoma(CRC) [6] and Hodgkin’s lymphoma(HL) [7]. This evidence concerns the gene CTLA4 and colorectal carcinoma.