Galectins are proteins of 30 kDa that can be found in the cellular nucleus, the cytosol and also in the extracellular space. They are members of the lectin family, a group of β-galactoside binding proteins. Galectin-1 [GAL-1] is a prototypical member of the galectin family of lectins. It is a divalent 14.5-kDa protein characterized by one carbohydrate recognition domain (CRD) that can occur as a monomer or as a non-covalent homodimer consisting of subunits of one CRD. GAL-1 is produced by a variety of vascular, interstitial, epithelial, and immune cells. GAL-1 is present both inside and outside cells, and has both intracellular and extracellular functions. The extracellular functions require the carbohydratebinding properties while the intracellular ones are associated with protein-protein interactions. Galectin-1, a member of carbohydrate-binding proteins with an affinity for b-galactoside, was found strong expressed in the isolated activated PSCs. Galectin-1 is widely distributed in many normal and pathological tissues and appears to be functionally polyvalent, such as regulating cell proliferation, differentiation and apoptosis, mediating tumor transformation, growth and so on. It is widely reported that Galectin-1 is overexpressed in many different types of digestive systém tumors, including gastric cancer, colorectal cancer and hepatocellular carcinoma.