Integrins are cell adhesion receptors that are heterodimers composed of non-covalently associated alpha and beta subunits. Integrin beta-4 pairs with alpha-6, and the heterodimeric integrin alpha-6/beta-4 is a receptor for laminin. Integrin alpha-6/beta-4 plays a critical structural role in the hemidesmosome of epithelial cells, and also plays a role in the invasive and metastatic phenotype of various cancers.