IL2 and metastatic melanoma: Current treatment options for patients with metastatic melanoma include several immunotherapeutic agents, such as high dose interleukin 2 (IL-2) [3], interferon (IFN) α-2b [4-6] and ipilimumab (an anti-cytotoxic T lymphocyte antigen-4 [CTLA4] antibody [7,8]).