SMAD2 and interstitial lung disease: Since Nedd4L accelerates the degradation of Smad2/3 and Tgfr1, thereby attenuating TGF-β signaling [42,43], the Zeb-1 feed forward loop (FFL) we identified here is likely to be a component of the larger pathway by which TGF-β signaling contributes to EMT, and thus to expansion and persistence of the myofibroblast compartment in ILD.