As a result of increased intestinal permeability in CrD, many bacteria mimic 57-68 and 62-75 gliadin sequences and activate cytokine cascade (IL-15, IL-2, TNF-α, and IFN-γ), and it is hypothesized that this leads to Th1-mediated immune reaction and causes the development of CD. This evidence concerns the gene IL2 and Cowden disease.