CTLA4 and melanoma: Immunotherapy is increasingly recognized as one of the most promising treatments for cancer therapy, and there has been a focus on the development of treatments aiming at some immunological checkpoint molecules such as anti-cytotoxic T-Lymphocyte-Associated Protein-4 (CTLA-4) and PD-1 in melanoma, kidney cancer, Hodgkin's disease, and lung cancer [1].