When we talk about stem cells, we are actually talking about a complicated series of things, including adult stem cells which are largely cells devoted to replacing individual tissues like blood elements or liver or even the brain.

I think we can allow the therapeutic uses of nuclear transplant technology, which we call cloning, without running the danger of actually having live human beings born.

The argument has been made in Congress that it is slippery slope if you allow therapeutic, what people people are calling therapeutic cloning, then you will get reproductive cloning.

David Baltimore Quotes