SMAD2 and renal fibrosis: Taken together, these experiments provide compelling evidence supporting the potential therapeutic efficacy of salidroside administration in the treatment of renal fibrosis by modulating multiple pathways including Sirt1/PGC-1α, PI3K/Akt/HIF-1α, Wnt1/Wnt3a β-catenin, TGF-β1/Smad2/3, TLR4/NF-κB, MAPK signaling pathways and ferroptosis.