CD47, also known as Integrin-associated protein (IAP), is a typical representative of the "marker of self" of targets expressed by all types of cells. CD47 is a glycoprotein with an immunoglobulin variable N-terminal domain, five transmembrane domains, and a short C-terminal intracellular tail with four variably different splicing isomers, resulting in four isoforms. CD47 is an immune cell group that plays a major role in targeted tumor immunotherapy. CD47 expressed by cancer cells interacts with SIRP-α and SIRP-γ expressed by NK cells to protect cancer cells from phagocytosis and elimination. CD47 was highly expressed in a variety of solid tumor cells and malignant hematoma cells, and its expression level was positively correlated with disease progression.