Yang et al. (2011) reported that NDRG2 exerts antifibrotic effects by inhibiting the phosphorylation of Smad3 and increasing the MMP2/TIMP2 ratio in a rat model of hepatic fibrosis. The role of NDRG2 in the TGF-β1/Smad3 pathway was further supported in a renal fibrosis model (Jin et al., 2017). In addition, a recent study demonstrated that the natural products Salvia miltiorrhiza and ligustrazine inhibit the proliferation of LX-2 by upregulating NDRG2 expression (Zheng et al., 2017). This evidence concerns the gene SMAD3 and renal fibrosis.