Immune checkpoint inhibitors (ICIs) including anti–programmed death-1 (PD-1) and anti–programmed death ligand-1 (PD-L1) have demonstrated a notable efficacy in metastatic colorectal cancer (mCRC) with mismatch repair deficiency (dMMR) or high microsatellite instability (MSI-H), which were characterized by a high mutational burden and a tumor-infiltrating lymphocyte enrichment (1, 2). This evidence concerns the gene CD274 and neoplasm.