Accumulating evidences indicated hyperuricemia was a risk factor for CKD [30] and several mechanisms have been suggested including the uric acid induced epithelial-to-mesenchymal transition (EMT) of renal tubular cells [31], activation of TGF-β/Smad3 pathway [32] and increased renal oxidative stress [7]. Here, SMAD3 is linked to hyperuricemia.