is being driven by the realities of federal funding and the political climate in the United States.

This relies on generating an embryo and destroying the embryo to remove the stem cells. Some people in our society believe that would be wrong,

They demonstrate that you can isolate the equivalent embryonic stem cells by alternative methods that may not raise the ethical questions,

I would say they also raise more questions than answers.

a huge chance to do pioneering high-risk research.

California could become the global center for stem cell research with that kind of investment and the talent that’s there. But within Harvard alone, we have as many outstanding scientists as arguably all of California....

[Neither method] really quells the ethical debate, … It’s not clear it’s going to answer all the critics.

The National Academy of Sciences guidelines for stem cell research prohibits payment to egg donors, and scientists in the U.S. have embraced those principles. There is a right way and a wrong way, and we...

I fully accept the ethical tradeoff.

I think this effort points out that science is done on a global scale. We can establish restrictions here in the United States, but the science moves forward in other countries.

I’m not sure you could ever satisfy the critics, … They could say, ‘Well, you might get it to work, but how often does it fail?’ If you adhere to this absolutist position, you have...

A process that dooms an otherwise normal embryo to later demise

We’re now probably two years behind where we’d hoped to be.

It’s not clear it’s going to work in human embryos. And in order to determine that we’ll have to actually do the research on human embryos and likely destroy some in the process.