As shown in Fig 1B, the serum levels of IGFBP-4 exhibited relatively good ROC profiles, with area under curve (AUC) values of 0.82 (P < 0.0001) and 0.72 (P = 0.0019), respectively, reflecting degrees of sensitivity and specificity for distinguishing SLE patients from healthy controls and from CKD controls. This evidence concerns the gene IGFBP4 and chronic kidney disease.