CTLA4 and renal cell carcinoma: Immunotherapy involving immune checkpoint inhibitors (ICIs), such as anti-programmed cell death receptor/ligand 1 (PD-1/PD-L1) and anti-cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) antibodies, plays a well-established role in the treatment of clear cell renal cell carcinoma (RCC).