Abstract: Galectins (Gals) constitute a 15-member class of β-galactoside-binding lectins which recognize N-acetyllactosamine. Despite lacking specific receptors, Gals form multivalent complexes with cell surface glycoconjugates containing suitable oligosaccharides and thus trigger intracellular signals to regulate cell survival and differentiation. Gals are classified into three groups on the basis of their structural architecture: proto, chimera and tandem types, with Gal-3 being the only representative of the chimeric type. Regarding intracellular localization, Gal-3 is found in both cell cytoplasm and nucleus. Extracellular Gal-3 can also be endocyted and, together with intracellular Gal-3, modulate diverse functions binding to intracellular molecules. While lacking a secretion signal peptide, Gal-3 is still secreted into the extracellular space by non-classical pathways potentially involving exosomes. Once secreted, Gal-3 binds to poly-N-acetyllactosamine in the extracellular matrix and membrane receptors, laying bridges to promote or inhibit intracellular events (Thomas and Pasquini, 2018).