A study combining nivolumab, plus the CTLA-4 inhibitor ipilimumab, and regorafenib, in refractory MSS CRC showed promising results in chemotherapy-refractory MSS CRC patients, with an ORR of 27.6%, a DCR of 68.2%, and a median PFS and OS of 4 and 20 months, respectively, in 29 patients (15). Here, CTLA4 is linked to colorectal carcinoma.