PDCD1 and non-small cell lung carcinoma: Today, immune checkpoint inhibitors (ICIs), such as the anti-PD-1 antibodies nivolumab [1, 2] and pembrolizumab [3] or the anti-programmed cell death ligand 1 (PD-L1) antibodies atezolizumab [4] and durvalumab [5], are recognized as standard second-line therapies for advanced or relapsed NSCLC, and use of ICIs is expanding to many other malignancies.