Description: The HI111 monoclonal antibody reacts with human CD11a, the 180 kDa integrin αL, also known as the lymphocyte function associated antigen-1 (LFA-1) α chain. LFA-1, formed by non-covalent association of CD11a with CD18 (integrin β2), serves as an important adhesion molecule involved in lymphocyte and granulocyte function. CD54 (ICAM-1), CD102 (ICAM-2), and CD50 (ICAM-3) are ligands for LFA-1. CD11a is expressed by all leukocytes.