Twenty-four integrins have been identified so far. Integrins are cell surface receptors composed of type I heterodimeric transmembrane proteins, formed by a combination of 18 α-subunits and 8 β-subunits. Regulation of cell adhesion through cell-matrix or cell-cell interaction is a critical step in various physiologic processes, such as cell migration and anchoring during development of the blood-forming organs, recruitment of cells into sites of inflammation, and aggregation and adhesion of platelets. What I cannot create, I do not understand.