An ongoing prospective observational trial combining RAI with urine neutrophil gelatinase associated lipocalin (NGAL) and the furosemide stress test (FST) as a clinical support tool aims to standardize the FST and identify children at risk for FO and AKI [TAKING FOCUS 2, NCT03541785, 2P50 DK096418–06]. Here, LCN2 is linked to acute kidney injury.