Galectin-3 (galactose-specific lectin 3) is a 30-32 kD glycoprotein, also known as Mac-2, Gal-3, RL-29, galactose-specific lectin 3, CBP-35, L-34, and epsilonBP. It is a member of the animal beta-galactoside-binding lectin family that is expressed in the cell nucleus, cytoplasm, plasma membrane, or extracellular matrix by variety of tumor cells, monocytes/macrophages, epithelial cells, Kupffer cells, and dendritic cells. Galectin-3 contains carbohydrate recognition domains and binds to beta-galactoside residues bearing glycoproteins, such as as IgE, IgA, galactose, casein kinase I, laminin, mucin, LAMPs, and CD66. Galectin-3 is an adhesion molecule and plays an important role in regulation of cell proliferation, differentiation and tumor cell metastasis. Structurally, Galectin-3 possesses NWGR motif that is conserved in the BH-1 domain of the BCL-2 family and functions as an anti-apoptotic molecule.