CTLA4 and renal cell carcinoma: Recently, immunotherapy agents targeting programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) axis alone or a combination with anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) monoclonal antibodies or antiangiogenic agents has greatly expanded the systemic treatment options for RCC [6, 9].