Recent studies of IL-2-based immunotherapy in metastatic melanoma have identified mainly LDH, performance status, number of metastatic sites and sites of metastases as independent prognostic factors (Sirott et al, 1993; Eton et al, 1998; Keilholz et al, 1998, 2002; Manola et al, 2000). The gene discussed is IL2; the disease is metastatic melanoma.