CTLA4 and colorectal cancer: A study of nivolumab monotherapy and nivolumab + ipilimumab (an anti-CTLA-4 antibody drug) combination therapy in patients with dMMR colorectal cancers (CheckMate-142 study) reported good outcomes with the ORRs of 31% and 55%, respectively, and the median PFSs was not reached in either group [66, 67].