First, lung cancer patients treated with PD-1 inhibitors are characterized by expressing effector-like phenotypes (HLA-DR+, CD38+, Bcl-2lo), co-stimulatory molecules (CD28, CD27, ICOS), a highly specific subset of proliferating CD8+ T cells in the peripheral blood, and high levels of PD-1 (32). This evidence concerns the gene CD8A and lung cancer.