IL10 and infection: Since IL-10 production was increased in Bhlhe40−/− mice and given the finding that blocking IL-10R signaling reversed the susceptibility phenotype seen after T. gondii infection (19), an anti-IL-10R Ab was used to determine if IL-10 blockade could improve the ability of the Bhlhe40−/− mice to control and clear their infection with P. yoelii.