Given the role of Bhlhe40 in regulating IL-10 and IFN-γ expression in other Th1-centric infections, it was hypothesized that Bhlhe40−/− mice would have an impaired ability to control infection with P. yoelii 17X, a non-lethal strain of the parasite, due to increased production of IL-10 and reduced production of IFN-γ. Here, IL10 is linked to infection.