In 109 advanced NSCLC patients receiving αPD‐(L)1 inhibitors, patients with a high immune effector score at baseline, predicated on high levels of NK cells and CD8+ PD‐1+ T cells with low plasma sPD‐L1 concentrations, had prolonged mPFS (not reached at 20 vs. 2.3 months) and mOS (not reached at 20 vs. 4.1 months), and better response to ICI therapies than patients presenting without a high score. Here, CD8A is linked to non-small cell lung carcinoma.