Pembrolizumab, a humanized monoclonal antibody against programmed death 1 (PD-1), is suggested as first-line therapy in NSCLC patients lacking a targetable driver gene mutation and a PD-L1 expression rate of 50% or more [1, 5, 6] because it prevents PD-1 from engaging PD-L1, which is an important predictor for response to immunotherapy using checkpoint inhibitors [7, 8]. This evidence concerns the gene CD274 and non-small cell lung carcinoma.