IFNG and Cowden disease: Other features of active CD are production of IgA antibodies to gliadin, a protein fraction of gluten (IgA-AGA) and the autoantigen tissue transglutaminase (IgA-tTG), up-regulation of both the pro-inflammatory cytokine interferon (IFN)-γ and the down-regulatory cytokine interleukin (IL)-10 [1], [3], [4].