Therefore, these IL-4 features, together with the development of CD being associated with a breach in oral tolerance, which results in altered regulation of the immune response against commensal microorganisms of the GI tract and generates an imbalance among Th1 (increase), Th2 (decrease) and Th17 (increase) cell populations in the activated state [18, 20], have led to the belief that this cytokine would be a good candidate for the development of new treatments for this IBD. The gene discussed is IL4; the disease is Cowden disease.