Finally, the differences in the onset and progression of ILD in congenital vs. conditional Nedd4-2−/− mice may be explained by age-dependent differences in the temporal and spatial activity of the CCSP promoter observed in previous studies of the CCSP-rtTA2S-M2 activator line that was used for inducible lung-specific deletion of Nedd4-2 [9,12]. This evidence concerns the gene SCGB1A1 and interstitial lung disease.