CD47 

CD47 is a glycoprotein that was first identified in 1990 as a protein that associates with integrins, hence its original name integrin-associated protein. CD47 interacts with SIRPα (CD172a or SHPS-1) and its family member SIRPγ, CD47 also interacts with integrins and secreted glycoprotein extracellular matrix protein thrombospondin-1 (TSP-1). Signaling through the CD47/SIRPα axis plays a role in various homeostatic processes, such as maintenance of erythrocytes, innate immune cells and T cells. Moreover, cancer cells and virus-infected and bacteria-infected cells can upregulate CD47 protein expression to prevent immune-mediated elimination.