CRC patients, those with MMR-deficient tumors, seem not to benefit from 5-FU-based chemotherapy.33-35 In addition, MSI tumors may be more responsive to irinotecan than microsatellite stable ones.36 A number of studies have shown that MSI tumors have a more favorable prognosis and are less prone to lymph node and systemic metastasis.3,15,37 In the 2010s, MSI-high colorectal tumors were classified as high-grade tumors whereas they are now regarded as relatively low-grade tumors with differing chemosensitivity and response to PD-L1 blockade therapy.38 Here, CD274 is linked to colorectal carcinoma.