NGAL (Neutrophil Gelatinase-Associated Lipocalin) is a member of Lipocalin family sharing a highly conserved fold with an eight-stranded antiparallel beta barrel, and it acts as a transporters, carrying small molecules to specific cells, and existing in monomeric and homo- and heterodimeric forms, the latter as a dimer with human neutrophil gelatinases (MMP-9). It is expressed in most tissues normally exposed to microorganism, and its synthesis is induced in epithelial cells during inflammation. NGAL has been implicated in a variety of processes including cell differentiation, tumorigenesis, and apoptosis, and can alter the invasive and metastatic behavior of Ras-transformed breast cancer cells by reversing epithelial to mesenchymal transition inducing activity of Ras. (1-5)
