FN1 and asthma: The periosteal can increase the adhesion of eosinophils to fibronectin, activate TGF-β-mediated (transforming growth factor-β-mediated) fibroblasts to increase the generation of type I collagen, and participate in the process of sub epithelial fibrosis through its fibrogenic function, promoting airway remodeling in asthma (38–41).