RBP4 and chronic kidney disease: New markers with particular potential in the diagnosis of CKD include uromodulin, KIM-1, fibroblast growth factor 23 (FGF23), urinary N-acetyl-β-D-glucosaminidase (NAG), NGAL, glomerular biomarker soluble urokinase-type plasminogen activator receptor (suPAR), and urinary retinol-binding protein 4 (RBP4).