Major surgery including cardiac surgery, complications such as hypotension or infection following surgery, and nephrotoxic drugs commonly prescribed in surgical patients are potential kidney exposures that can stress renal tubule cells and thus cause AKI [10], making cardiac surgery patients an appropriate at-risk population for risk stratification with the [TIMP-2]•[IGFBP7] test. Here, IGFBP7 is linked to acute kidney injury.