However, CD47 is broadly expressed on hematopoietic cells and other normal tissues 17, and the enhanced expression of CD47 has been reported on tumor cells in a variety of hematopoietic malignancies and solid tumors, such as leukemia 6, bladder cancer 18, astrocytoma 19, prostate cancer 20, and leiomyosarcoma 21. The gene discussed is CD47; the disease is leukemia.