Plasma and urinary NGAL levels have been shown to have similar discriminative performance and sensitivity for AKI requiring dialysis34, although exhibiting different temporal profiles—with urinary NGAL performing better at predicting mortality or dialysis when measured as a peak value during the first 24 h following admission and the optimal temporal window for sampling both urinary and plasma NGAL being approximately 6–24 h after emergency department presentation35. This evidence concerns the gene LCN2 and acute kidney injury.