CXCL1 and bacterial urinary tract infection: Figure 2 shows NGAL levels in children with and without UTI. Three additional markers, IL-1β, CXCL1, and IL-8, also had AUCs greater than 0.85 and specificities greater than 76%. Supplement Table S3 shows the cutoff for each marker that maximized the Youden index with the corresponding sensitivity and specificity and the cutoff that minimized the distance to (0,1) on the ROC curve with the corresponding sensitivity and specificity.