In CRC, anti-PD-1 (pembrolizumab and nivolumab) and anti-CTLA-4 inhibitors (nivolumab) were approved by the FDA, and their treatment efficiency is influenced by the microsatellite instability and tumor mutation environment in each CRC patient.9-11 A total of 69% of patients treated with anti-PD-1 inhibitors have 12 months of overall survival after pembrolizumab and nivolumab treatment.12 Interestingly, a combination of nivolumab with ipilimumab could efficiently improve the therapeutic effect.13 Even so, a large number of CRC patients are not responsive to anti-PD-1 and anti-CTLA-4 treatment. Here, CTLA4 is linked to colorectal carcinoma.