The work by Elizondo et al. using Ahr knockout mice on a resistant background found that systemic absence of AhR caused a decrease in FoxP3+ regulatory T-cells in infected animals in the 4th and 6th week of infection and a concomitant increase in IL10 secretion by restimulated pLN cells after 6w, while Leishmania Ag specific secretion of IFNγ and IL4 were not affected in infected animals (24). Here, IL4 is linked to infection.