They can never, ever, become a baby.

Our experiments are very clear. You inhibit this gene and you get a clone that has no way of ever implanting. But this clone can make embryonic stem cells.

It is clear now that every experiment published by Hwang will have to be confirmed in some way before being believed.

Our work is the first proof-of-principle study to show that altered nuclear transfer not only works but is extremely efficient.

We do experiments with animals and we know there is a major problem, which is not solved, so one should not do this with humans because humans are not guinea pigs.

It is not responsible at this stage to even consider the cloning of humans.

This paper demonstrates clearly that it doesn't matter if a stem cell has been derived from a cloned embryo or from a fertilized embryo.

The success of this procedure in no way precludes the need to pursue all forms of human embryonic stem cell research, ... Human embryonic stem cells are extraordinarily complicated. If we are ever to realize their therapeutic potential, we must use all known tools and techniques in order to explore the mechanisms that give these cells such startling characteristics.

Knowing more about the process and about the precise areas of the brain that are affected will give us options for exploring future therapies.