The development and clinical deployment of immune checkpoint inhibitors (ICIs), particularly those targeting programmed death-1 receptor (PD-1), its ligand PD-L1, and cytotoxic T-lymphocyte antigen-4 (CTLA-4), have yielded unprecedented responses in a range of malignancies including but not limited to melanoma,1,2 non-small cell lung cancer (NSCLC),3,4 and renal cell carcinoma (RCC).5 This evidence concerns the gene CTLA4 and renal cell carcinoma.