Integrins are heterodimeric integral membrane proteins composed of an alpha chain and a beta chain. CD103/ITGAE is 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, CD103/ITGAE forms the E-cadherin binding integrin known as the human mucosal lymphocyte-1 antigen, and is preferentially expressed in human intestinal intraepithelial T-lymphocytes (IEL). In addition to a role in adhesion, CD103/ITGAE may serve as an accessory molecule for IEL activation. [taken from NCBI Entrez Gene (Gene ID: 3682)].