In the submucosa of the small intestine, starting with the the action of tissue transglutaminase type 2 which unfolds gluten, a cascade of events occurs, causing a Th1 response that stimulates B lymphocytes that release IgE and other immunoglobulins [26] which play a important roles in the appearance of urticaria and AD, and a stimulation of Th2 mediated by T-lymphocytes which produces the release of pro-inflammatory cytokines, such as TNF-α and interferon gamma (IFNγ), among others [27], and that play important roles in several types of immune-mediated dermatitis, such as psoriasis. This evidence concerns the gene IFNG and Alzheimer disease.