Immune checkpoint inhibitors (ICIs), such as monoclonal antibodies targeting programmed cell death protein-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), have shown promise in CRC treatment (2). The gene discussed is PDCD1; the disease is colorectal carcinoma.