Further, our study shows that NEDD4-2 protein levels are reduced in patients with IPF and identifies extra- and intracellular disease mechanisms that link Nedd4-2 deficiency to impaired mucociliary clearance and dysregulation of TGFβ signaling, two abnormalities that have been implicated in the pathogenesis of IPF6,58. The gene discussed is TGFB1; the disease is idiopathic pulmonary fibrosis.