It recognizes a transmembrane glycoprotein of 95kDa, identified as CD18 or integrin -2 (Workshop III). It complexes non-covalently with either L, M, or X integrin (CD11a, b, or c) to form the heterodimers, LFA-1, Mac-1, and p150,95, respectively. LFA-1 is the receptor for three members of the Ig supergene family of proteins, ICAM-1 (CD54), ICAM-2 (CD102), and Mac-1 and p150,95 bind to ICAM-1, fibrinogen, and iC3b. ICAM-3 (CD50). CD18/CD11 heterodimeric molecules are involved with cell/cell and cell/extracellular adhesion in immune and inflammatory responses. This MAb blocks these cellular interactions.