In addition to IL-2 (approved for metastatic kidney cancer and metastatic melanoma in 1992 and 1998), IFN-α has been approved by the USFDA for the treatment with hairy cell leukemia (1986) (11), and TNF (tasonermin) was licensed in Europe for irresectable soft tissue sarcoma in the 1999. The gene discussed is IL2; the disease is hairy cell leukemia.