The HI111 monoclonal antibody specifically binds to the 180 kDa integrin alpha chain. This type I transmembrane glycoprotein associates with CD18 (integrin beta2) to form the heterodimeric glycoprotein CD11a/CD18. This heterodimer is also known as the lymphocyte (leukocytes) function associated antigen-1 (LFA-1) that is expressed on all leukocytes. LFA-1 is an adhesion molecule involved in lymphocyte and granulocyte functions. LFA-1 mediates adhesion of lymphoid cells to the vascular endothelium in association with its ligand, and the intracellular adhesion molecule-1 (ICAM-1), CD54. Other ligands are ICAM-2 (CD102) and ICAM-3 (CD50). Synonyms: LFA-1alpha, Lymphocyte (Leukocyte) function-associated antigen 1 alpha chain, ITGAL