SMAD3 and renal fibrosis: The authors also highlighted that in the HFD mouse, renal interstitial fibrosis, and phosphorylation of SMAD3 (mothers against decapentaplegic homolog 3, acts as a regulator of cell proliferation and differentiation, its phosphorylation plays a key role in renal fibrosis) are significantly increased with respects to the values observed in mice fed a low-fat diet (LFD).