PDCD1 and lung cancer: Lung cancer is a leading cause of cancer-related deaths in China,[1,2] with non-small cell lung cancer (NSCLC) accounting for approximately 85% of cases.[3] A recent implementation of immune checkpoint inhibitors (ICIs), such as antibodies against programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1), has shifted the therapeutic paradigm for NSCLC.