Neutrophil gelatinase-associated lipocalin (NGAL) is a protein that is primarily expressed in neutrophils, a type of white blood cell, as well as other cells such as kidney tubular cells. NGAL is involved in various physiological and pathological processes, particularly in the context of inflammation, infection, and kidney injury. NGAL is a member of the lipocalin protein family, which are small extracellular proteins that bind and transport small hydrophobic molecules. It can bind to a variety of ligands, including iron-containing siderophores, bacterial lipopolysaccharides, and certain matrix metalloproteinases (MMPs). This binding activity contributes to the role of NGAL in modulating the immune response and tissue remodelling.