Expression analysis of cellular genes, performed also at short time points (3, 6, and 9 h post-infection) showed that the expression of the inflammatory genes coding for IFN-β (interferon beta) and IL-6 (interleukin 6), involved in innate immune responses during viral infection, increased over time (Figure 2C,D), in parallel with the raise in viral load. Here, IL6 is linked to infection.