CTLA4 and neoplasm: Anti-CD25-IgG or its anti-CD25-F(ab′)2 derivative [44,55,56] and anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) antibody [57] conjugated NIR-PIT agents can selectively eliminate the local Tregs only within the tumor microenvironment (TME), resulting in upregulation of the anti-tumor immune responses [47].