AKT1 and infection: Nonetheless, the results showing blockade of infection by PI3K inhibitors added at 0 and 2 hpi are consistent with the increased phosphorylation of Akt at 15 and 30 min post-infection seen in the Western blot (Figure 2A), which marks the increased PI3K kinase activity at those early time points, and suggest that PI3K activation is important at the initial stage of infection.