These include the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blocking antibody ipilimumab (for advanced melanoma), two antibodies blocking PD-1, pembrolizumab (for advanced melanoma, NSCLC, and head and neck cancer) and nivolumab (for advanced melanoma, NSCLC, RCC and Hodgkin lymphoma), and one antibody blocking PD-L1, atezolizumab (for advanced urothelial carcinoma). Here, CTLA4 is linked to head and neck cancer.