CD47 (also known as Rh-associated protein, GP42, integrin-associated protein (IAP), and neurophilin,) is an immunoglobulin-like protein that interacts with its receptor, Signal-regulatory protein alpha (SIRPα), on macrophages. This binding interaction regulates transmigration, oxidative burst cytokine production, and phagocytosis, creating a “don’t eat me” signal. CD47 is ubiquitously expressed on the surface of normal cells, but is overexpressed in numerous cancer cells, where it is thought to contribute to the resistance of tumors to phagocyte-dependent clearance.