It has been reported that repeated applications of 2,4-dinitrochlorobenzene (DNCB) to mouse skin induced AD-like skin lesions, which is associated with a significant increase in serum immunoglobulin E (IgE) and T-helper (Th) 2 cytokines such as interleukin-4 (IL-4) and IL-13 at the chronic dermatitis site (Kitagaki et al., 1995; Harada et al., 2005). The gene discussed is IL4; the disease is Alzheimer disease.