Embryonic stem cells can become any other cell in the body, a capability researchers hope one day to direct toward healing organs ravaged by disease. In the U.S., President George W. Bush restricted federal funding of human embryonic stem cell research in 2001, with just $24.8 million doled out in 2004. But in a dramatic rejection of Bush's policy, the state of California in the past year became the world's largest single backer of stem cell research, a move spearheaded by Palo Alto, Calif.–based housing developer Robert Klein.