Although there are different disease phenotypes, the hallmark of allergic asthma is a type 2 immune response, characterized by IL-4, IL-5, and IL-13 secretion by T helper 2 (Th2) lymphocytes, IgE secretion, recruitment and activation of eosinophils, mast cells, dendritic cells and epithelial cells [12]. The gene discussed is IL4; the disease is allergic asthma.