PDCD1 and non-small cell lung carcinoma: In recent years, immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1) have attracted global attention, and their development and application have fundamentally changed the landscape of treatment for newly diagnosed patients with advanced NSCLC, especially those without targeted genetic mutations (Peters et al., 2019).