Further, urine Klotho levels in AKI patients were strikingly higher than those in non-AKI patients at the first postoperative time (1.69 (1.02, 2.68) ng/umol vs. 0.52 (0.23, 0.84) ng/umol, p < 0.01), and remained significantly higher up to day 3 postoperatively. The gene discussed is KL; the disease is acute kidney injury.