TGFB1 and pulmonary fibrosis: In fact, elevated serum levels of degraded decorin are found in fibrotic lung diseases and, for this reason, this form of decorin has been proposed as a biomarker for lung fibrosis (Kehlet et al., 2017) while the wild-type form could be considered as a possible therapeutic agent because of its antifibrotic activity exerted by targeting TGF-β signaling.