CD8A and neoplasm: To assess the impact of the tumour environment on the phenotypic changes of CD39 + CD8 + T cells, we performed a comparative analysis of PD-1 and Tim-3 expression on pleural CD39 + CD8 + T cells obtained from LUAD with EGFRwt or initially diagnosed EGFRmu, as well as MPE with acquired resistance to EGFR-TKI (Fig. 3C).