Development of BRAF inhibitors vemurafenib (PLX4032)4–6 and dabrafenib and immune checkpoint blockade antibodies which target either cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) or programmed cell death protein 1 (PD-1)7,8 have dramatically altered the therapeutic landscape of melanoma in the past few years9,10. The gene discussed is CTLA4; the disease is melanoma.