IGF2 and infection: To confirm the promoter activity at P3 and P4 upon rHSVQ infection, GBM cells stably expressing the firefly-luciferase reporter gene under the control of either IGF2 P3 (IGF2P3-Luc) or IGF2 P4 (IGF2P4-Luc) were infected with or without rHSVQ (MOI = 0.1) for 24 hours.