TIMP2 and acute kidney injury: We have previously shown that RIPC successfully reduced the occurrence of AKI after cardiac surgery in high-risk patients, and that the effectiveness of this intervention was dependent on the transient release of two kidney cell cycle arrest biomarkers immediately after the procedure: tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 ([TIMP-2]·[IGFBP7]).9