CD47 and breast cancer: CD47 was first identified as a tumor antigen on human ovarian cancer in the 1980s; since then, CD47 has been found to be overexpressed on multiple hematologic and nonhematologic malignancies, including chronic myeloid leukemia (CML), non-Hodgkin's lymphoma (NHL) [15], multiple myeloma [16], breast cancer [17], pancreatic cancer [18], nonsmall cell lung cancer (NSCLC) [19, 20], and other solid tumors.