CD4 and infection: A subset of IFN-γ/IL-10 double-producing CD4+ T cells have been observed in humans infected with Plasmodium [8,10], and mouse models of malaria suggest that IFN-γ/IL-10 double-producing cells are an important source of IL-10 that limit immunopathogenesis of malaria [11] at the cost of inhibiting control of the infection [12].