Galectin-3 is a protein that in humans is encoded by the LGALS3 gene. Galectin-3 is a member of the lectin family, of which 14 mammalian galectins have been identified.Galectin-3 is approximately 30 kDa and, like all galectins, contains a carbohydrate-recognition-binding domain (CRD) of about 130 amino acids that enable the specific binding of β-galactosides.Galectin-3 (Gal-3) is also a member of the beta-galactoside-binding protein family that plays an important role in cell-cell adhesion, cell-matrix interactions, macrophage activation, angiogenesis, metastasis, apoptosis.
Galectin-3 is encoded by a single gene, LGALS3, located on chromosome 14, locus q21–q22. Galectin-3 is expressed in the nucleus, cytoplasm, mitochondrion, cell surface, and extracellular space.