The benefit of programmed death-1/programmed death ligand-1 (PD-1/PD-L1) immunotherapy, particularly of nivolumab, pembrolizumab and atezolizumab, in the second-line setting of patients with non-small cell lung cancer has been documented in randomized clinical trials, showing improvements in global survival and in the overall response rate. This evidence concerns the gene PDCD1 and non-small cell lung carcinoma.