GBM4 (upper), GBM8 (middle), GBM13 (middle), and BT74 (lower) were infected with G207, FΔ6, or MG18L at MOI of 1.5. A. Single step virus growth analysis. Cells and media were collected and virus yields determined. B. MG18L infection strongly activates Akt in GSCs. Collected cells were processed for western blotting with antibodies to ICP4 (immediate-early virus gene expression), phospho-Akt (Ser473 and Thr308), and total Akt.