CD81 and infection: Since the surface levels of CD59 and other HCV entry (co)receptors are not apparently downregulated and since the permissiveness to VSVpp infection is unaffected in the HCV 420Bla+ stable cells (Figure 7, 8, and 9), it is conceivable that the reduction of CD81 surface level and exclusion to HCV reinfection by actively replicating HCV is not resulted from a defect in cell growth.