This product reacts with a 90kD protein involved in the homing of lymphocytes to peripheral lymph nodes (CD62L or L-selectin). L-selectin is expressed on most T and B lymphocytes, neutrophils, monocytes and eosinophils. Pre-incubation of lymphocytes with the antibody completely and specifically blocks binding of lymphocytes to high endothelial venules (HEV) in vitro and the migration of lymphocytes to lymph nodes in vivo.