IL13 and allergic disease: Dupilumab is an IgG4 human monoclonal antibody (mAb) that binds IL-4Ra [9, 10] with subsequent inhibition of IL-4R signaling induced by both IL-4 and IL-13, and down-regulation of TH2 inflammation in a variety of allergic disorders, including atopic dermatitis, asthma, and possibly other allergic diseases.