C. sinensis could exert anti-fibrotic activity by mediating TGF-β1/Smad signaling pathway, and attenuate renal fibrosis in 5/6 nephrectomy rats by abrogating the expression of TGF-β1, Smad2/3, TβRI, TβRII, p-Smad2/3, α-SMA, and FSP1, and upregulated Smad7 to inhibit EMT (Pan et al., 2013). Here, SMAD2 is linked to renal fibrosis.