In this Forbes Q&A, Matthew Herper interviews James Thomson, who's recently started his own company, Cellular Dynamics International, which is focused on testing experimental drugs for heart side effects. Rather than cave into the hype surrounding regenerative medicine, he sees much bigger opportunities for stem cells as a research tool and in drug discovery. "It's hard to predict the future, but my guess is 20 years from now if you look backwards, 90 percent of the value of these cells will be in things that don't make the front pages. It will be things like drug screening, which is kind of boring, but it does get drugs to market that are safer and faster," he says.