Galectins are a family of widely expressed β-galactoside-binding lectins in metazoans. The 15 mammalian galectins have either one or two conserved carbohydrate recognition domains (CRDs), with galectin-3 being able to pentamerize; they form complexes that crosslink glycosylated ligands to form a dynamic lattice. The galectin lattice regulates the diffusion, compartmentalization and endocytosis of plasma membrane glycoproteins and glycolipids. The galectin lattice also regulates the selection, activation and arrest of T cells, receptor kinase signaling and the functionality of membrane receptors, including the glucagon receptor, glucose and amino acid transporters, cadherins and integrins (PMID:26092931). Galectin-3 self-associates via inter- and intramolecular NTD–CRD interactions and intermolecular NTD–NTD contacts driven by hydrophobic interactions. Galectin-3 also self-associates when it binds to glycoconjugates, such as those present on the cell surface, resulting in aggregation of these glycoconjugates or the formation of galectin lattices (PMID:28893908). The extracellular domains of transmembrane receptors can be modified with monosaccharides and polysaccharides to create binding sites for the carbohydrate recognition domain of galectin-3. The IDR of galectin-3 self-associates with other IDRs of neighboring galectin-3 molecules to form a multivalent network with modified transmembrane receptors (PMID:30951647).