Galectins are a family of animal lectins with an affinity for beta-galactosides. This family has at least 14 identified members. Galectins share similarities in the CRD （the carbohydrate recognition domain）. Galectins are synthesized as cytosolic proteins. Though localized principally in the cytoplasm and lacking a classical signal peptide，galectins can also be stimulated to secretion by non-classical pathways or alternatively targeted to the nucleus. Galectins are involved in modulating cell-cell and cell-matrix interactions. Galectin-8 is a tandem-repeat-type member of the galectin family，consisting of 2 CRDs attached by a linker peptide. Galectin-8 is greatly expressed in lung carcinomas，a number of forms of prostate carcinomas，in addition to other tumor cells. Galectin-8 attaches to a subset of cell surface integrins to modulate ECM-integrin interactions. Once immobilized，Galectin-8 promotes cell adhesion by ligation and clustering of cell surface integrin receptors. On the other hand，as a soluble ligand，Galectin-8 can inhibit cell adhesion.
