Indeed, the radioresistant MCF7/C6 cells showed a remarkedly reduction of phagocytosis compared to the MCF7 cells, and in agreement with literature35, the CD47 antibody significantly promoted macrophage-mediated phagocytosis on both MCF7 and radioresistant MCF7/C6 cells (Fig. 4a and Supplementary Fig. 5a, b), indicating that CD47 is an effective immune checkpoint target to synergize RT in BC treatment. Here, CD47 is linked to breast cancer.