Integrins are a family of cell-adhesion receptors that bind ligands in the extracellular matrix or ECM to mediate cell-matrix adhesions. They transition between an active and an inactive state. In the active form, they serve as mechanical linkers connecting the cytoskeleton to the extracellular matrix. Integrin comprises noncovalently associated alpha and beta glycoprotein subunits, forming a transmembrane heterodimer. The intracellular C-terminal tail of the beta subunit interacts with actin filaments in the cytosol through adaptor proteins such as talin and paxillin. Integrin’s large N-terminal extracellular domains bind to specific amino acid sequence motifs in ECM proteins, such as the RGD sequence in fibronectin. The adhesion complex formed transmits signals bidirectionally across the plasma membrane with the help of effector proteins, thus facilitating cell motility, growth, and survival.