IFNG and infection: It is conceivable that akin to L. major infection in p110δ deficient mice [41] and infection with L. major clone SD [40], the low IL-10 response could permit low levels of IFN-γ to more efficiently activate macrophages leading to effective parasite killing in vivo. Thus, although lpg2- L. major-infected mice also produce significantly less IFN-γ, it is conceivable that low levels of IFN-γ may be more efficient at activating macrophages for more efficient parasite control when IL-10 levels are also correspondingly low.