Therefore, the maximum point ofYouden index (sensitivity + specificity - 1) is taken as the best cutoff value,and the maximum sensitivity and specificity of biomarkers (TNF-α, IL-2,IL-6, NGAL) in CSA-AKI detection is calculated by the abscissa and ordinate ofcorresponding receiver operating characteristic (ROC) curve. Here, IL6 is linked to chromosome-type aberration frequency.