integrin subunit alpha D(ITGAD) Homo sapiens This gene belongs to the beta-2 integrin family of membrane glycoproteins, which are are composed of non-covalently linked alpha and beta subunits to form a heterodimer. It encodes the alpha subunit of the cell surface heterodimers and is involved in the activation and adhesion functions of leukocytes. The gene is located about 11kb downstream of the integrin subunit alpha X gene, another member of the integrin family. It is expressed in the tissue and circulating myeloid leukocytes. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2015]