Each year, around 100,000 people worldwide receive solid organ transplants, and from the day of their surgery to the day they die almost all of them have to take daily immunosuppressant drugs to prevent the body from attacking the new organ. But an experimental procedure in which patients receive some of the donor's bone marrow in addition to the organ hopes to eliminate the need for lifelong drug therapy. Elie Dolgin talks to the scientists who are rejecting the idea of transplantation as usual.