Food and Drug Administration (FDA) approved CTLA4 inhibitors such as ipilimumab, PD1 inhibitor nivolumab and PD-L1 inhibitor pembrolizumab in high mismatch repair-deficient high metastatic CRC [12], along with newly emerging drugs in combination with or without radiotherapy are just some of the ongoing clinical trials on CRC patients. Here, CTLA4 is linked to colorectal carcinoma.