Description: The 3.9 monoclonal antibody reacts with human CD11c, the 150 kDa integrin αX chain. CD11c non-covalently associates with β2 integrin to form the CD11c/CD18 heterodimer. This complex is expressed on monocytes, granulocytes, macrophages, NK, dendritic cells and subset of T and B lymphocytes. CD11c/CD18 binds to CD54, iC3b and fibrinogen and plays a role in leukocyte adhesive interactions.