In addition, a more favorable prognosis of anti-PD-1/PD-L1 checkpoint immunotherapies is observed in patients with higher expression of PD-L1 in the tumor microenvironment (TME) and without EGFR and ALK mutations17,18, suggesting that PD-L1 expression in the TME is a critical predictive marker for checkpoint immunotherapies of NSCLC. This evidence concerns the gene ALK and non-small cell lung carcinoma.