Immune checkpoint blockades, targeting cytotoxic T‐lymphocyte‐associated protein 4 (CTLA‐4), programmed cell death protein 1 (PD‐1), or programmed cell death ligand 1 (PD‐L1), have exhibited notable efficacy in a defined subset of cancer patients, encompassing non‐small cell lung cancer (NSCLC), metastatic melanoma, and microsatellite instability tumors.[1] However, the broad clinical success of immune activation treatment remains limited. The gene discussed is PDCD1; the disease is cancer.