IL2 and melanoma: The scope of cancer immunotherapy grew from the use of immune stimulating cytokines like interleukin-2 (IL-2) and Interferon alpha (IFNα) in renal cell carcinoma and melanoma, to the use of immune modulating antibodies against Cytotoxic T cell Lymphoma Antigen 4 (CTLA 4) and Programmed Death 1 (PD-1) molecules.