LACK antigen from Leishmania braziliensis, Leishmania guyanensis, and Leishmania amazonensis induces the production of IFN-γ and IL-10 in peripheral blood mononuclear cells (PBMC) from patients with cutaneous leishmaniasis (CL), and IL-10 in those of naïve individuals (7, 9–12). The gene discussed is IL10; the disease is cutaneous leishmaniasis.