CD47 and neoplasm: CD47 is a protein that can be detected in a variety of cancer kinds CSCs (CD47 is a transmembrane immunoglobulin widely expressed on CSCs of various tumor types, including LCSCs, PCSCs, and BCSCs (103, 104), and inhibits phagocytosis by macrophages by binding to SIRPα on the surface of macrophages, thus exerting the “don’t eat me” signal.