Carl June, MD, Director of Translational Research at the Abramson Cancer Center, reports on recent research advances in the treatment of patients with chronic lymphocytic leukemia, some of whom have achieved an exceptional, unprecedented antitumor response from a therapy based on molecularly engineered T-cells developed at Penn. In the pilot study of three patients, two achieved complete remission and the third experienced a remarkable antitumor response that was impossible with previously available treatments.