PDCD1 and non-small cell lung carcinoma: Antibodies against the programmed cell death protein 1 (PD-1) receptor and its ligand PD-L1, among other immune checkpoint inhibitors, have delivered unprecedented clinical benefit in various human malignancies, including melanoma, non-small-cell lung cancer (NSCLC), head and neck squamous cell carcinoma, and bladder cancer [8–11].