Rabbit Polyclonal antibody to CD109

CD109 is a glycosylphosphatidylinositol (GPI)~linked glycoprotein that belongs to the alpha2~macroglobulin family of thioester containing proteins. CD109 is associated with TGF~beta receptor I (TbRI) and inhibits TGF~beta signaling. Cleavage of CD109 at its Furin cleavage site results in the release of its large amino~terminal domain, which then binds to the TGF~beta receptor I to inhibit TGF~beta signaling. CD109 is expressed on a subset of CD34+ bone marrow cells and mesenchymal stem cells, activated platelets, activated T cells, endothelial cells, and a wide variety of tumors. Elevated CD109 expression has been considered a diagnostic/prognostic marker for several types of cancers.