SMAD2 and chronic kidney disease: Present study evaluated the potency of quercetin for CKD therapy with in vitro study in a cell model of CKD by modulating the production of TNF-α, TGF-β1, and MDA as inflammation cytokines, fibrosis, and oxidative stress marker and SMAD2, SMAD3, SMAD4 and SMAD7 as inflammation and fibrosis genes.