Malignant gliomas, the most common type of primary brain tumors, are one of the most deadly cancers. Even when given the best available treatment, patients with these tumors face a poor prognosis, a situation that has changed little in the past several decades. Recently, researchers identified brain tumor stem cells that are responsible for tumors' resistance to therapy and recurrence. Since conventional radiotherapy and chemotherapy have had limited success in the treatment of malignant gliomas, we developed an oncolytic adenovirus, Delta-24-RGD, that is able to efficiently eradicate both brain tumor bulk and stem cells, indicating its potential to induce complete tumor remission in patients with malignant gliomas. Currently, this novel agent is being tested in a phase I clinical trial at the Brain Tumor Center, The University of Texas MD Anderson Cancer Center.