PDCD1 and non-small cell lung carcinoma: Immune checkpoint inhibitors (ICIs) targeting T-cells receptors cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death 1 (PD-1), and its ligand PD-L1, aimed at increasing or activating immune cells to reverse the immunosuppressive state, are a promising therapeutic strategy for NSCLC bone metastasis48.