In driver mutation-negative advanced non–small cell lung cancer (aNSCLC), chemotherapy with anti–programmed cell death 1 (PD1) or its ligand (PD-L1) immune checkpoint inhibitor therapy (ICI) is standard of care for patients with PD-L1 expression (ie, tumor proportion score) of less than 50% (PD-L1 low). Here, PDCD1 is linked to lung cancer.