Thus, in lung cancer, we and others have shown that the most robust correlation of survival is with the magnitude of the intratumoral infiltration with CD8+ cytotoxic tissue-resident memory T cells (TRM).2 3 While infiltrating immune cells can control tumor progression, it is clear that tumors defend themselves by generating a microenvironment that impairs and attenuates the function of immune cells. This evidence concerns the gene CD8A and lung carcinoma.