TGFB1 and renal fibrosis: The classical signaling pathways in renal fibrosis include TGF-β1/Smad, nuclear factor-κB (NF-κB), Notch, Wnt, Hedgehog, phosphatidylinositol-3 kinase (PI3K/AKT), Janus kinase/signal transducers and activators of transcription (JAK-STAT), RHO/Rho coil kinase (ROCK), and tumor necrosis factor α (TNF-α) (20, 21).