CD18, also known as the integrin beta 2 subunit. It is expressed on all leukocytes. CD18 associates with integrin alpha chains CD11a, CD11b, and CD11c to form LFA-1 (CD11a/CD18), Mac-1 (CD11b/CD18), and αXβ2 (CD11c/CD18), respectively, playing a critical role in leukocyte adhesion. The CD18 integrin complexes bind to ligands such as ICAM-1 (CD54), ICAM-2 (CD102), ICAM-3 (CD50), iC3b, and fibrinogen. The M18/2 antibody is capable of blocking tumor cell metastasis and enhancing cell adhesion.
