TGFB1 and infection: Moreover, the expression of the cytokines IL-1β, IFN-γ, IL-6, TNF-α, and TGF-β was higher in HDV-∆L-HDAg mice than in HDV-WT at days 14 and 21 post-infection, in agreement with the increased liver damage observed at these time points; however, only the expression of TNF-α was significantly higher (Figure 5B).