IGFBP7 and acute kidney injury: Considering the fact that TIMP-2 and IGFBP7 are cell-cycle arrest proteins expressed in renal tubular cells during the periods of cellular stress or injury [8], it is tempting to speculate that urinary TIMP-2 and IGFBP7 are involved in the early pathological changes of AKI and carry the diagnostic probability of early renal injury.