SPP1 and chronic kidney disease: A few other molecules were investigated as potential kidney biomarkers of CKD in children: clusterin, osteopontin, N-Acetyl-β-d-amino Glycosidase (NAG), symmetric and asymmetric dimethylarginine (SDMA, ADMA), or Trefoil Factor3 (TFF3) and results of recent studies were presented in Table 1.