It remains unclear why some patients' tumors can be cured with chemotherapy, whereas other tumors that appear to be nearly identical are completely chemoresistant. Dr. Gutierrez focuses on this issue in a particularly high-risk subset of T-cell acute lymphoblastic leukemia, a disease that most commonly affects older children and young adults. His goals are to define the molecular basis of resistance to conventional chemotherapy in patients with this disease, and to leverage this knowledge to develop a therapeutic strategy to restore chemosensitivity. Ultimately, this could lead to significant improvements in clinical outcome for these patients.