In a significant breakthrough, investigators at Weill Cornell Medical College and the University of California, San Francisco, have been able to overcome resistance of a form of leukemia to targeted therapy, demonstrating complete eradication of the cancer in cell and animal studies. Their study, published in the May 19 issue of Nature, shows that an investigational drug, RI-BPI, developed at Weill Cornell, in combination with the drug Gleevec shut down stem cells responsible for about one-third of acute lymphoblastic leukemia (ALL), a cancer of white blood cells that affects young children as well as older adults.