Cell-transplant therapies that offer promise for fighting cancer and other diseases also come with a risk: rogue cells that can turn deadly. Now researchers at Baylor College of Medicine in Houston report on a method that engineers a so-called suicide switch into transplanted cells that, when activated with a drug, rapidly kills off the ones that cause harm. The method, tested in children undergoing stem-cell transplants to treat leukemia, wiped out the cells that turn on the body of the patient, a complication called graft-versus-host disease
