CD47 and central nervous system cancer: To rule out direct inhibitory effects of anti-CD47 on glioma cells, we performed an in vitro proliferation assay and found no impairment of cell growth upon anti-CD47 treatment in two different glioma lines (T387, P = n.s.; T3832, P = n.s.), whereas the same concentration of anti-CD47 led to a highly significant increase of in vitro phagocytosis of four different glioma lines when cocultured with bone marrow-derived macrophages of NSG-Ccr2RFP/wt-Cx3cr1GFP/wt (T387, P = 0.003; T4121, P < 0.0001; T3832, P = 0.002; and T3691, P = 0.002) (SI Appendix, Fig. S4).