For example, Keilholz et al. analyzed 631 cases of IL-2-based treatment of stage IV melanoma to compare median survival between patients who treated with IL-2 alone, IL-2 plus chemotherapy, IL-2 plus IFN-alpha and IL-2, and chemotherapy plus IFN-alpha, suggesting that only the addition of IFN-alpha to IL-2 was associated with prolonged survival [6]. The gene discussed is IL2; the disease is melanoma.