FGF23 and chronic kidney disease: Novel biomarkers such as Neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, Interleukin-6 (IL-6) and Fibroblast Growth Factor (FGF-23) can improve the early diagnosis of AKI and CKD (193–197), predict clinical outcome (198, 199) and help quantitation of severity in CKD (200).