CXCR4 and acute lymphoblastic leukemia: Four antigens, highly expressed by the three ALL (Dg, R2 and R3) were selected for the ADCC assays: CD19 (clone HIB19), CD24 (adhesion molecule, in B cells; clone ML5), CD184 (IL-4 receptor; clone 12G5), and CD220 (insulin receptor; clone B6.220).