In 2006, Izuhara et al. [5] first identified that periostin is a downstream molecule of interleukin-4/-13 (IL-4/13), signature cytokines of type 2 inflammation, signalling, and first reported its relationship to allergic diseases, observing the accumulation of periostin in thickened basement membranes of bronchial epithelial cells in asthma patients. This evidence concerns the gene IL4 and allergic disease.