LCN2 and acute kidney tubular necrosis: Neutrophil gelatinase-associated lipocalin (NGAL) rises rapidly after tubular epithelial injury, is typically highest in acute tubular necrosis (intermediate in HRS, lowest in prerenal states), carries independent prognostic information and appears relatively insensitive to volume status or diuretics, although urinary tract infection can artifactually elevate levels and must be excluded [36,61,62,63].