IL4 and atopic asthma: Allergic or atopic asthma, also termed extrinsic or T2 high asthma, is the most common form, characterized by a predominant TH2 cell immune response hallmarked by the production of the cytokines interleukin 4 (IL-4) and IL-5, and IL-13, eosinophilic inflammation, airway hyperreactivity, and increased serum IgE levels [1, 2].