TIMP2 and acute kidney injury: NephroCheck® (Astute Medical, San Diego, CA, USA) is an immunoassay test that measures the urinary concentrations of two cell-cycle arrest biomarkers, tissue inhibitor metalloproteinase-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7), and provides a quantitative risk index that combines them into a single numerical ratio\([TIMP-2] [IGFBP7]/1000), which is a reliable predictor of acute kidney injury (AKI) in critically ill patients, the results of which can be expected within 1 hour of sample collection (1).