Literature thresholds for urinary NGAL diagnosis of AKI vary with cause and context of AKI and range from 72 ng/ml in children after cardio-pulmonary bypass surgery [24] to 680 ng/ml in adults after cardio-pulmonary bypass surgery [25]; Using these extremes in the two studies cited, the demonstrated sensitivities for the subsequent creatinine-based diagnosis of AKI ranged respectively from 42% to 62.5%. This evidence concerns the gene LCN2 and acute kidney injury.