Current protein AKI biomarkers; ranging from urinary or plasma neutrophil gelatinase-associated lipocalin, urinary IL-18, to tissue inhibitor of metalloproteinases-2* insulin-like growth factor-binding protein 7, were reported in critical care or cardiac surgery settings to predict RRT or death, with AUROC of 0.6–0.85. This evidence concerns the gene LCN2 and acute kidney injury.