Integrins are a family of transmembrane proteins involved in diverse processes including cell adhesion, signal transduction, cell migration, and differentiation. They exist as heterodimers consisting of noncovalently linked alpha and beta subunits. Integrin complexes span the plasma membrane and link the cytoskeleton with the extracellular matrix. In mammals there are 18 alpha and 8 beta subunits that can assemble into 24 distinct integrin heterodimers with alternative splicing adding even more diversity.
