CTLA4 and renal cell carcinoma: Immune checkpoint inhibitors (ICI) therapy is a type of immunotherapy that targets drugs that inhibit PD1(Programmed Death-1), PD-L1(Programmed Death Ligand-1), and CTLA-4(Cytotoxic T Lymphocyte-associated Antigen-4) and has demonstrated encouraging outcomes in the treatment of a variety of tumors4,5, including non-small-cell lung cancer(NSCLC)6, renal cell carcinoma (RCC)7, hepatocellular carcinoma (HCC)8, and melanoma9.