CD55 and infection: Similarly, expression of human decay-accelerating factor (DAF) (also known as CD55), which serves as an attachment factor for coxsackievirus B3 (CVB) (2, 5) and is required for apical infection of cultured enterocytes (6), is also not sufficient to mediate high levels of viral replication when the virus is delivered by the enteral route, which occurs only upon IFN-α/β receptor deletion (7).