Patients with all forms of KS and individuals at risk of KS, including HIV-1-infected individuals and older people of Mediterranean origin, show CD8+ T cell and Th1-type activation and increased peripheral blood levels of IL-1, IL-6, TNF-α, and IFN-γ, or show an oligoclonal expansion of CD8+ T cells (Ensoli et al., 2000). This evidence concerns the gene IFNG and Kaposi's sarcoma.