The interaction between programmed death‐1 (PD‐1) on T cells and programmed death‐ligand 1 (PD‐L1) on malignant cells, the so‐called effector phase, plays a crucial role in the immune escape of cancer cells, as shown by the clinical efficacy of blocking PD‐1/PD‐L1 in current cancer immunotherapy.11 The gene discussed is PDCD1; the disease is cancer.