This gene encodes a glycoprotein expressed on the surface of NK cells, platelets, monocytes and a subset of T cells. It is a member of the Ig-superfamily containing 2 Ig-like domains of the V-set. The protein mediates cellular adhesion of platelets and megakaryocytic cells to vascular endothelial cells. The protein also plays a role in megakaryocytic cell maturation. Alternative splicing results in multiple transcript variants.