2013: Year of the Stem Cell

Researchers have already safely injected stem cells into patients with neurodegenerative diseases and spinal cord injuries -- and they've seen the potential to vastly improve lives.

Marcus Hilton has probably been going blind since he was born, though he didn't really begin to notice that something was wrong until he was seven or eight. Several years after that, he was officially diagnosed with Stargardt disease, the leading cause of juvenile blindness. Thirty-four years of decline later, his retinas irreparably damaged, he is unable to drive, read fine print, or recognize people from a distance.

For Knut Olstad, devastation came much more suddenly. Having quit smoking and taken up cross-country skiing and bicycling in an early mid-life crisis, he was 45 years old and on what he described as the vacation of his life, conquering 25 mountains on the Tour de France route. On the last descent of the twenty-fifth mountain, on what might even have been the final turn of the entire trip, a car veered