Integrins are heterodimeric integral membrane proteins composed of an alpha chain and a beta chain. This gene encodes an I-domain-containing alpha integrin that undergoes post-translational cleavage in the extracellular domain，yielding disulfide-linked heavy and light chains. In combination with the beta 7 integrin，this protein forms the E-cadherin binding integrin known as the human mucosal lymphocyte-1 antigen. This protein is preferentially expressed in human intestinal intraepithelial lymphocytes (IEL)，and in addition to a role in adhesion，it may serve as an accessory molecule for IEL activation. [provided by RefSeq，Jul 2008]