ACTB and infection: As shown in Figure 3A, beginning at 12 hpi, the densitometric ratio of the β-actin and LC3-II bands, an accurate indicator of autophagic activity, was much higher in SVA-infected BHK-DicerΔ- and BHK-Ago2Δ- cells than in the corresponding mock-infected BHK-21 cells, indicating that SVA infection promoted autophagy (P < 0.01).