CD8A and non-small cell lung carcinoma: Thommen et al. demonstrated that the immunologic function and metabolism of intratumoural CD8+T lymphocytes differ according to PD-1 expression, and the presence of TILs with high PD-1 expression is correlated with an improved response to PD-1 blockade and with increased OS in NSCLC.9 Teng et al. proposed that the TME be stratified into four types based on T-cell infiltration and PD-L1 as follows: type I, PD-L1+TIL+; type II, PD-L1- TIL-; type III, PD-L1+TIL-; and type IV, PD-L1- TIL+.41 According to this classification, group 1 in the present study may be relevant to type IV TME.