Integrins are heterodimeric cell surface receptors that play a pivotal role in cell adhesion and migration, as well as in growth and survival. ntegrins not only transmit signals to cells in response to the extracellular environment (outside-in signaling), but also sense intracellular cues to alter their interaction with the extracellular environment (inside-out signaling). Most Integrin receptors bind ligands that are components of the extracellular matrix, including fibronectin, collagen and vitronectin. Signals transduced by Integrins play a role in many biological processes, including cell growth, differentiation, migration and apoptosis.