ISG15 and infection: Interestingly, consistent with HBV infection in HepG2-NTCP system, the sC69∗ + pLMS showed significantly lower innate immune responses than WT regarding the expression of IL29, ISG15, and RIG-I mRNA levels 4 days post-infection and TNFα 7 days post infection (p < 0.05), while the other ISGs expression seemed to show overall lower trend in sC69∗ + pLMS than that of WT but without statistical difference (Figure 5B), indicating that sC69∗ could attenuate the expression of some ISGs.