Dupilumab (SAR231893/REGN668) is a fully humanized anti–IL-4Rα MAb, which reduced asthma exacerbations when long-acting beta-adrenoceptor agonists (LABAs) and ICSs were withdrawn from patients with persistent asthma, moderate-to-severe asthma, and who had a blood eosinophil count >300 cells/μL or a sputum eosinophil level >3%. Here, IL4R is linked to asthma.