The cut-off value of urinary NGAL that differentiates between patients with AKI and those with other causes of renal impairment was 286.3 μg/g creatinine (area under ROC curve is 0.909) (sensitivity 95.5% and specificity 76.1%) with a positive predictive value (PPV) of 65.6 and negative predictive value (NPV) of 99.2 (Figure 3). This evidence concerns the gene LCN2 and acute kidney injury.