Allergic asthma is associated with wheezing, bronchoconstriction, and type 2 or allergic inflammation characterized by the presence of type 2 cytokines, such as IL-13 and IL-4 (4, 5), which induce the production of chemokines involved in the recruitment and activation of inflammatory cells such as eosinophils (6–9). This evidence concerns the gene IL4 and allergic asthma.