G, HBMEC were transiently transfected with control siRNA or PI3K p110α siRNA. Cells expressing either control siRNA or PI3K p110α siRNA were challenged with T. gondii 48 h after transfection. Cell lysates were subject to immunoblotting as indicated. Densitometry data are shown as above and represent means ± SEM of 3 experiments. Results shown are representative of 3-4 independent experiments. 