PDCD1 and cancer: ORR was 40% for dMMR CRC, 71% for dMMR non‐CRC, and 0% for pMMR CRC.55 Blockade of PD‐1/PD‐L1 signaling brings durable efficacy for a subset of patients showing high tumor mutation burden (TMB) across almost all types of cancer, including many rare tumor types, characterized by dMMR/MSI‐H.62 The combination of nivolumab (PD‐1 blocker) plus ipilimumab (CTLA‐4 blocker) in dMMR/MSI‐H CRC was recently reported.