An experimental therapy uses a person’s weak immune system to fight deadly blood cancers. Stanley Riddell is a researcher at the Fred Hutchinson Cancer Research Center in the U.S. state of Washington. He and his colleagues added molecules to immune cells that attack cancer cells. They put the modified cells back in the patient, where they multiply and fight cancer. “So, that’s the one interesting thing about this. It doesn’t require repeated treatments or repetitive cycles of chemotherapy,” said Riddell. “That’s what I think in the future may be most important for patients that it’s a single treatment instead of many months of treatment.” It has shown great promise in small trials with patients. In one study of 35 patients with a type of leukemia, 94 percent experienced a complete remission. Fifty percent to 80 percent of patients with other blood cancers also saw a reduction in symptoms. Riddell said, “This is encouraging because these are all patients who have failed all conventional therapies, including many kinds of bone marrow and stem cell transplants.”