CTLA4 and non-small cell lung carcinoma: Immunotherapies targeting cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death 1 (PD-1) have been used for the treatment of melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), and Hodgkin's lymphoma 14-21.