The pathogenesis of psoriasis in the context of HIV-1 infection has been associated with many immunologic events that include a decrease in the number of Langherhan's cells, but also with a potential epidermal proliferative effect of HIV-1 itself, an altered CD8:CD4 ratio and high synthesis of nitric oxide driven by HIV-1 in macrophages [56]. The gene discussed is CD8A; the disease is psoriasis.