IFNG and infection: Similarly, the protective response to Toxoplasma gondii is associated with IFN-γ, although in the absence of IL-10, infected animals may die due to extensive early tissue damage [128, 129]. In vitro approaches suggest that the sources of IL-10 in these infections are Th1 cells and these IL-10-producing Th1 cells still maintain their ability to activate macrophages [121].