Merchant ML, et al. - Experts intended to identify preoperative candidate urine biomarkers in patients undergoing cardiac surgery. The researchers concluded that pre-operative urine measurement of complement factor B (CFB) or histidine rich glycoprotein (HRG) significantly enhanced the current post-surgery acute kidney injury (AKI) risk stratification for a more restrictive definition of AKI. Findings revealed that HRG, but not CFB or clinical risk stratification, predicted AKI defined by Kidney Disease Improving Global Outcomes (KDIGO), however, the ability of these biomarkers to predict risk for dialysis-requiring AKI or death could not be reliably evaluated due to a small number of patients with either outcome.