In the Keynote-142 phase II open-label trial9 of nivolumab, an anti-PD1 antibody, in patients with metastatic MSI-H colorectal cancer who had been unable to tolerate previous chemotherapy or whose disease had progressed, ORR and disease control rates were similar in Lynch versus non-Lynch MSI-H colorectal cancer (33 versus 29 per cent, and 70 versus 75 per cent, respectively). This evidence concerns the gene PDCD1 and colorectal cancer.