The AUC of plasma NGAL (≥280 ng/ml) for the diagnosis of septic vs. non-septic AKI was 0.77 (95 % CI: 0.63–0.90) with a sensitivity of 0.75 and specificity of 0.76, while that of urine NGAL (≥150 ng/mg creatinine) was 0.70 (95 % CI: 0.59–0.82) with a sensitivity of 0.69 and specificity of 0.60 for a diagnosis of septic AKI. The gene discussed is LCN2; the disease is acute kidney injury.