[To check out a six-minute video featuring two eminent researchers and Technology Review's editor in chief discussing the hows and whys of embryonic stem-cell research -- with spectacular color graphics and images -- click here. Note: You can pause the video at any time.]

Embryonic stem (ES) cell research, we hope, will be moving from the laboratory to the clinic in the coming years. The promise of this technology -- and the associated scientific challenge -- is enormous (see "Stem Cells Reborn"). Worldwide, 17 million people die every year from cardiovascular disease, more than 200 million suffer from diabetes, and millions more fall ill from a wide range of other disorders that may one day be treatable with stem cell thera-pies.