Galectins are a family of animal lectins defined by shared characteristic amino-acid sequences and affinity for β-galactose-containing oligosac-charides . Galectin-3 contains one carbohydrate recognition domain (CRD) and a proline- and glycine-rich N-terminal domain through which is able to form oligomers. Galectin-3 is widely expressed in many normal tissues and a variety of tumors. It is found intracellularly in nucleus and cytoplasm or secreted outside of cell,being present on the cell surface or in the extracellular space . Galectin-3 is involved in various biological processes including cell growth,adhesion,differentiation,apoptosis,angiogenesis,immune response,neoplastic transformation and metastasis .
