FABP1 and acute kidney tubular necrosis: Liver-type fatty-acid binding protein (L-FABP), a proximal-tubule protein induced by hypoxia and oxidative stress, typically mirrors these gradients (acute tubular necrosis > HRS > prerenal) and has been linked in exploratory work to subsequent HRS risk, adding a pathophysiologic lens to early risk stratification [36,40,61].