NGAL concentrations rise rapidly, within 2–6 h, and are detectable in plasma when AKI is potentially limitable or reversible16,17 A meta-analysis of 307 studies involving 1200 patients, reported an area under the receiver operator characteristic curve (AUROC) of plasma NGAL (pNGAL) for predicting AKI post-cardiac surgery as 0.78 (95% confidence interval 0.67 to 0.87). This evidence concerns the gene LCN2 and acute kidney injury.