CTLA4 and hereditary clear cell renal cell carcinoma: Over the last decade, with the development of monoclonal antibodies that target the regulatory immune “checkpoint” receptors CTLA-4, PD-1, and PD-L1, immune therapy has now become standard therapy for diverse malignancies including melanoma, lung cancer, and renal cell carcinoma with the list of responsive tumors rapidly expanding (2–11).