Some studies have reported diminished soluble Klotho levels in patients with type 2 DM [94,95], whereas a reduced renal Klotho expression has been observed in biopsies from patients with early stages of DKD [96], suggesting that soluble Klotho may be an early biomarker for predicting renal impairment in type 2 diabetic patients [97]. This evidence concerns the gene KL and diabetic kidney disease.