CD81 and infection: In contrast to the results observed in Huh7 naïve cells, ectopic expression of CD81 in 420Bla+ stable cells did not restore the permissiveness to HCVpp infection (Figure 12C), which was consistent with the observation that the level of exogenously overexpressed CD81 in 420Bla+ cells was also lower than that observed in Huh7 cells overexpressing exogenous CD81 (Figure 12B).