In the work described here, we sought to determine: a) whether anti-CD47 antibodies could induce phagocytosis of pre-B-ALL lymphoblasts and mature B-cell blasts by macrophages, b) whether anti-CD47 antibodies induce phagocytosis of otherwise live cells and thereby result in their cell death by phagocytosis, and c) how anti-CD47 antibodies induce phagocytosis. The gene discussed is CD47; the disease is acute lymphoblastic leukemia.