KL and congenital rubella syndrome: Seibert et al. [22] have reported that serum α-Klotho was increased in AKI patients and progressively decreased in patients with CKD stage 1 to 5, and in this study, the etiology of AKI includes infection, parenchymal renal disease, acute tubular necrosis, prerenal kidney failure, cardiorenal syndrome (CRS), and other renal disease.