CST3 and chronic kidney disease: Cystatin C had the highest AUC for outcome prediction (0.630; 95% confidence interval [CI]: 0.556 to 0.704; P < 0.001), followed by 2021 CKD-EPI eGFRcr-cys (AUC: 0.625; 95% CI: 0.551 to 0.699) (Table S1).