SFTPC and interstitial lung disease: The importance of dysregulated ENaC activity in the pathogenesis of ILD in congenital Nedd4-2−/− mice is also supported by the observation that this epithelial ion transport defect was already present in 10-day-old mice with normal lung morphology, i.e., prior to the onset of histological signs of ILD (Figure 2), as well as previous studies in Nedd4-2fl/fl/Sftpc-rtTA/Cre mice with the constitutive deletion of Nedd4-2 under control of the SP-C promoter [11] and mice with the constitutive overexpression of the α and β subunits of ENaC in the lung [37].