High levels of IL-10 have been found both in the blood and serum of human subjects with pulmonary TB [43, 44] and reductions in bacterial load have now been shown in Il10−/− mice on both the C57Bl/6 and BALB/c backgrounds as well as CBA/J mice that received sustained treatment of Mtb infection in the presence of an anti-IL-10R monoclonal antibody [45]. The gene discussed is IL10; the disease is pulmonary tuberculosis.