With respect to the diagnosis of DKD, the areas under the receiver operating characteristic curve (AUCs) for urinary NGAL, clusterin, and cystatin C were 0.816 (95% confidence interval [CI], 0.741–0.891), 0.775 (95% CI: 0.694–0.857), and 0.803 (95% CI: 0.722–0.884), respectively. The gene discussed is CST3; the disease is diabetic kidney disease.