CD47 and breast cancer: CD47, as a “don't eat me” signal, can cause “cell escape,” prevent phagocytosis of macrophages, and cause “cell aggregation.” Besides playing an important role in cell migration and adhesion, angiogenesis, cell proliferation, and apoptosis, CD47 is also widely expressed in a variety of tumors, such as ovarian cancer, bladder cancer, breast cancer, skin cancer, and hematopoietic malignant tumors.