Notably, IL-17A+IFN-γ+ CD4+ T cells are prominent in T cell-dependent colitis models (Hue et al., 2006; Kullberg et al., 2006) and have also been recovered from the intestinal lesions of human CD patients (Annunziato et al., 2007; Cosmi et al., 2008). Here, IFNG is linked to Cowden disease.