In a large cohort study of 312 patients, plasma klotho levels did not differ across CKD stages and were not significantly associated with GFR or other parameters of calcium-phosphate metabolism, which contradicted previous studies in which serum alpha-klotho concentration was associated with estimated GFR (eGFR) and was significantly decreased in CKD patients [33, 34]. The gene discussed is KL; the disease is chronic kidney disease.