Discover Magazine looks at one of the noteworthies of the stem cell research community: "The value of therapeutic cloning has long been clear to Lanza, who did his early work with South African heart transplant pioneer Christiaan Barnard. Starting from those early days, Lanza understood that the barrier to tissue transfer was rejection by the recipient. From an entire organ to a dose of embryonic stem cells, if the tissue's DNA came from anyone else, the transplant would be rejected without the aid of harsh immunosuppressive drugs. 'The treatment could be worse than the problem,' Lanza found. But embryonic clones, the source of an endless supply of stem cells imprinted with one's personal DNA, could alter the equation in favor of the patient and augur a paradigm shift in medicine on par with the changes brought about by antibiotics and vaccines ... With the ability to become all of the blood cells - including your immune cells, red blood cells, all of your blood system, as well as vasculature, [hemangioblasts] have been biology's holy grail. What we discovered is that we can create literally millions or billions of these from human embryonic stem cells. ... we can use transient, intermediate cells like hemangioblasts as a toolbox to fix the adult so you don't have to have limbs amputated, so you may not have to go blind, to prevent heart attacks."