SR‐B1 deficiency reduced the tumor load and PD‐L1 level of colitis‐induced or APCmin/+‐induced CRC, triggered the anti‐colon effect of anti‐PD‐1 in colitis‐induced CRC, which controlled the TAM, M‐MDSCs, G‐MDSCs, PD‐L1, and increased the HLA‐B levelin colitis‐induced CRC, regulated the expression of genes in APCmin/+‐induced CRC, and regulated the intestinal microbiota of colitis‐induced CRC. Here, CD274 is linked to colitis.