Panels of tubular-injury biomarkers: kidney injury molecule-1, interleukin-18, liver-type fatty acid-binding protein and neutrophil gelatinase-associated lipocalin show promise for distinguishing structural ATN-AKI from functional HRS–AKI, although evidence remains limited and validated cut-offs are needed [32,36,41,74,82]. Here, LCN2 is linked to acute kidney injury.