1) A diverse family of extracellular (e.g., laminin) and cell surface (e.g., NCAM) glycoproteins involved in cell-cell and cell-extracellular matrix adhesion, recognition, activation, and migration.

2) Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.