NGAL (lipocalin-2) is a lipocalin family protein that plays important roles in innate immunity, inflammation, and atherosclerosis. It was originally identified as a 25 kD protein covalently bound to gelatinase from human neutrophils. NGAL is a critical component of innate immunity because of its ability to bind iron-siderophore complexes and limit bacterial growth. It is also produced by injured epithelia and is one of the most promising markers for renal epithelial injury and cardiovascular disease (CVD).