TGFB1 and renal fibrosis: Thus, Klotho is a critical negative regulator of canonical Wnt signaling and suppresses renal fibrosis in the obstructed kidney model by simultaneously suppressing multiple growth factor signaling pathways such as fibroblast growth factor-2 (FGF-2), Wnt, and TGF-β1 (Guan et al., 2014).