However, in Abcb1a-deficient mice that also develop enhanced colitis after Helicobacter infection and IL-17RA blockade, co-blockade of IFN-γ did not decrease disease severity (42), suggesting that increased IFN-γ may not be causative for the enhanced disease observed in the absence of IL-17. This evidence concerns the gene IFNG and Helicobacter pylori infectious disease.