The CBRM1/5 monoclonal antibody binds with the 165 kDa human adhesion glycoprotein CD11b, which forms, together with the 95 kDa CD18 （integrin β2） a complex known as Mac-1.
CD11b is expressed on the surface of activated lymphocytes, a subset of natural killer cells, granulocytes, and monocytes.
It functions as a receptor in cell-cell and cell-matrix interactions and as a receptor for iC3b, ICAM-1, ICAM-2, and ICAM-3 intercellular adhesion molecules.
The CBRM1/5 specifically reacts with the activation-specific epitope of the Mac-1 molecule, in the I domain on the alpha chain near the ligand binding site.
The antibody has been reported to inhibit the cellular adhesion mediated by Mac-1.
