CD11c is a 150 kDa adhesion glycoprotein that associates with beta2 integrin to form the CD11c/CD18 heterodimer that binds CD54 (ICAM-1) and fibrinogen. It is expressed on NK cells, a subset of B and T cells, granulocytes, monocytes, and macrophages. It functions in cytotoxic T cell killing and in neutrophil and monocyte adhesion to endothelium.1-6