IGFBP7 and acute kidney injury: Numerous biomarkers have been investigated to predict AKI, such as neutrophil gelatinase-associated lipocalin (NGAL), tissue inhibitor metal proteinase (TIMP)-2, and insulin growth factor binding protein (IGFBP)-7, improving the diagnosis and giving prognostic information about the timing to start or stop a renal replacement therapy (RRT) [3,4,5].