We have previously reported high expression of MDR1 in GBM and demonstrated that down-regulation of MDR1 via Akt/NF-κB pathways upon transfection of the Ad-DKK3 gene augmented the anti-tumor effects of temozolomide in GBM cells and in a GBM-xenograft model17. The gene discussed is ABCB1; the disease is glioblastoma.