Abnormal thickening of the reticular basement membrane with increased deposition of extracellular matrix (ECM) proteins, fibronectin, collagen types I, III, and V, hyaluronan, laminin α2/β2, tenascin, and versican within the lamina reticularis is one of the hallmarks of airway remodeling in asthma and has been observed in both children and adults with mild to severe and fatal asthma in several histological studies (Roberts, 1995; Laitinen et al., 1997; Elias et al., 1999; Zeiger et al., 1999; Boulet et al., 2000; James et al., 2012a; Burgess et al., 2016). This evidence concerns the gene TNC and asthma.