CD8A and neoplasm: Indeed, the mutational burden, defined by the number of mutations per megabase in the coding regions of the tumor genome, is significantly lower in EGFR-mutated NSCLC compared to wild-type EGFR tumors [21] and it has been shown that EGFR mutations are associated with an immunosuppressive tumor microenvironment [22–24] with a lower CD8+ T cell infiltration than in wild type EGFR NSCLC.