CTLA4 and neoplasm: This strategy enhances the body’s immune response against tumors, and in the context of HNCs is currently being explored, especially based on ICIs, e.g., via targeting PD-1/PD-L1 or CTLA-4 (cytotoxic T-lymphocyte-associated protein 4) and adoptive cell therapies, e.g., tumor-infiltrating lymphocytes or chimeric antigen receptor T cell (CAR-T cell) therapy.