New studies in zebrafish have shown that a 50-year-old antipsychotic medication called perphenazine can actively combat the cells of a difficult-to-treat form of acute lymphoblastic leukemia (ALL). The drug works by turning on a cancer-suppressing enzyme called PP2A and causing malignant tumor cells to self-destruct. The study led by Alejandro Gutierrez MD and A. Thomas Look MD of Dana-Farber/Boston Children''s Cancer and Blood Disorders Center and Jon Aster MD PhD of Dana-Farber Cancer Institute and Brigham and Women's Hospital suggested that developing medications that activate PP2A while avoiding perphenazine's psychotropic effects could help clinicians make much-needed headway against T-cell ALL