From the BCH site:
Despite the initial successes, though, further islet transplants have been plagued with mixed results. Even when the transplants are successful, patients require immunosuppressant medications to prevent their immune system from attacking the transplanted cells—medications that come with their own, potentially serious, side effects.
In fact, in many cases, cell transplant seems to trade one unhealthy immune response for another. “Both diabetes itself, and its potential cure by way of cell transplantation, are plagued by the same problem—the immune system attacks the islet cells,” explains Fiorina. “In order to truly cure diabetes, we needed to pinpoint exactly why this happens. And then prevent it.” This seems to be the nature of research. When an advance is made, it often presents a whole new series of problems to be solved. Can they know that it requires "just a little more study?"
mk or b_b, my two pals in research, do you think this is putting the cart before the horse?