CTLA4 and nonpapillary renal cell carcinoma: In the past few years, with the development of immunotherapy, immune checkpoint inhibitors (ICIs) targeting programmed death 1/programmed death ligand 1 (PD-1/PD-L1) and cytotoxic T lymphocyte associated antigen 4 (CTLA-4) brought new hope for the treatment of ccRCC (3).