While all IgG2σ anti-CD47 mAbs suppressed leukemia growth similar to IgG1 anti-CD47 mAbs in the Kasumi-3 model (Figure 3b), anti-leukemic effects of the IgG2σ anti-CD47 mAbs were less pronounced in the HL60 and MV4-11 models (Figures 3a and c). This evidence concerns the gene CD47 and leukemia.