ACTB and infection: The protein levels of DDX10 in PCV3-infected PK-15 cells were significantly decreased at 12, 24, 36, and 48 h post-infection (hpi) (Fig. 1A), which was further confirmed by an analysis of the relative densitometric ratios of DDX10 and β-actin (the corresponding internal reference) (Fig. 1B, P < 0.05).