Preclinical studies in mouse models defined a role for IL-13 in many of the pathophysiologic features of asthma, including eosinophil recruitment, AHR, and tissue remodeling, as described by mucus hypersecretion, matrix dysregulation, and smooth muscle hyperplasia (Gour and Wills-Karp, 2015). Here, IL13 is linked to asthma.