Another mechanism involved in the inhibition of TGF-β pathway by vitamin D analogs in renal fibrosis has been described: maxacalcitol blocks the autoinduction of TGF-β1 expression through the recruitment of a complex between VDR and the SMAD3 phosphatase PPM1A to the TGFB1 promoter, causing SMAD3 dephosphorylation and release from the promoter and, consequently, attenuating TGFB1 gene expression [54]. Here, SMAD3 is linked to renal fibrosis.