CD235a, also known as Glycophorin A, is the most abundant sialoglycoprotein on the surface of human erythrocytes. It plays a crucial role in reducing red blood cell aggregation and maintains blood fluidity. CD235a serves as a receptor for various pathogens, including the influenza virus, Plasmodium falciparum (the parasite causing malaria), and hepatitis A virus, making it significant in the context of infectious diseases. Its expression and function are essential for the proper physiological function of red blood cells.