It is therefore noteworthy that Calles et al. recently reported detection of PD-L1 expression in KRAS-mutant NSCLC specimens from 44, 20, and 13% of current smokers, former smokers, and never-smokers, respectively (P = 0.03) (50), which has been reported to correlate with a favorable response to PD-1/PD-L1-targeted therapy (29, 51). This evidence concerns the gene PDCD1 and non-small cell lung carcinoma.