Impressively, although single antibody of either receptor can induce phagocytosis, dual antibody showed an obvious synergy in the macrophage phagocytosis of the radioresistant BC cells (Fig. 4f and Supplementary Fig. 6c), indicating that HER2–NF-κB-mediated CD47 transcriptional activation is responsible for the potential tumor resistance to anti-CD47 immunotherapy. This evidence concerns the gene CD47 and breast cancer.