Nmu-/- mice share features with AD patients, as do ft/ft mice; for example, Nmu-/- mice with an otherwise AD-resistant B6 genetic background have dry skin and develop AD-like skin inflammation characterized by a combined Th1/Th2 cytokine response together with a modest increase in levels of the IL-17-promoting cytokine IL-23, although as for ft/ft mice, repeated hapten exposure is required to induce AD-like inflammation. The gene discussed is IL17A; the disease is Alzheimer disease.