CTLA4 and non-small cell lung carcinoma: Targeting programmed cell death protein-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T lymphocyte-associated protein-4 (CTLA-4) therapy has resulted in responses in various tumors such as Hodgkin’s lymphoma and non-small cell lung cancer [11,12].