In the Sapphire study, [TIMP-2]·[IGFBP7] exhibited an AUC of 0.80 for development of AKI (stage 2 or 3) within 12 hours and alone IGFBP7 and TIMP-2 each exhibited an AUC of 0.76 and 0.79 respectively (Figure 2 and Table S1 in Additional file 1). This evidence concerns the gene IGFBP7 and acute kidney injury.