CD47 and breast cancer: CD47 was first identified as a tumor antigen on human ovarian cancer, since then CD47 has been found to be overexpressed on multiple hematologic and nonhematologic malignancies, including chronic myeloid leukemia, non-Hodgkin's lymphoma [13], multiple myeloma [14], breast cancer [15], non-small-cell lung cancer (NSCLC) [16, 17], and pancreatic cancer [18].