The gene encodes a member of the integrin alpha chain family of proteins. Integrins are heterodimeric integral membrane proteins composed of an alpha chain and a beta chain that function as cell surface adhesion molecules. The encoded preproprotein is proteolytically processed to generate light and heavy chains that comprise the alpha 3 subunit. This subunit joins with a beta 1 subunit to form an integrin that interacts with extracellular matrix proteins including members of the laminin family. Expression of this gene may be correlated with breast cancer metastasis. [provided by RefSeq, Oct 2015].