In the peripheral blood and tumor tissues of patients with non‐small cell lung cancer (NSCLC), MAIT cells, especially the CD8+ subset, show significant enrichment and high expression of the chemokine receptor CXCR6; this feature is closely related to the responsiveness to anti‐PD‐1/PD‐L1 immunotherapy [202, 215, 216]. The gene discussed is CD8A; the disease is lung cancer.