IGFBP7 and acute kidney injury: In 2014, the United States Food and Drug Administration (FDA) has approved the production of tissue inhibitor of metalloproteinases-2 (TIMP2) and insulin-like growth factor binding protein 7 (IGFBP7) markers, involved in growth phase cell-cycle arrest of tubular epithelial cells, for their usefulness in the early detection of moderate to severe AKI defined as KDIGO stages 2 and 3.