CTLA4 and non-small cell lung carcinoma: Without targetable mutations, treatments involve immune checkpoint inhibitors (ICIs) alone or combined with chemotherapy to target key proteins like Programmed Death 1 (PD-1), PD-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), which has advanced the management of NSCLC with BM.