In Microsatellite Stability (MSS)-type CRC tumor-bearing mice, changes in gut microbiome affected the expression of immune-related cytokines IFN-γ and IL-2 in the tumor microenvironment, resulting in a different therapeutic effect of PD-1 antibody, and Prevotella_sp._CAG:485 and Akkermansia may maintain the normal efficacy of PD-1 antibody (87). This evidence concerns the gene PDCD1 and colorectal carcinoma.