CTLA4 and melanoma: The tumor with genetic mutation is often treated with targeted therapy, such as vemurafenib and dabrafenib.[19,20] Immunotherapy for malignant melanoma mainly includes antihuman cytotoxic T-lymphocyte antigen-4 (CTLA4) monoclonal antibody, programmed death 1 (PD-1) inhibitor, and programmed death-ligand 1 (PD-L1) inhibitor.[21] All of them are immune checkpoint inhibitors acting through receptor blockade at specific points in the immune response.