PDCD1 and non-small cell lung carcinoma: The emergence of immune checkpoint inhibitors (ICIs), including programmed cell death 1 (PD-1) or programmed cell death ligand 1 (PD-L1) antibodies and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) antibodies, has completely revolutionized the situation of neoadjuvant chemotherapy for operable locally advanced NSCLC.