As reported by Australia's ABC Online last night:

Britain's famous science broadcaster and expert on reproductive technology, Lord [Robert] Winston, [Professor of Fertility Studies at Imperial College, London and science broadcaster for his BBC television programs], says the potential benefits of embryonic stem cell research are being hyped.

He says scientists have been talking up their work, and the possibility of curing diseases in the near future, to push through more flexible laws on embryonic stem cell research....

Lord Winston says there are many problems with embryonic stem cell research and believes part of the reason the work may be hyped by scientists is so they can convince politicians to introduce less restrictive laws in order to source more embryos for their research....

And there are scientific problems associated with embryonic stem cell research aside from the ethical question of having to sacrifice embryos, as Professor [Peter] Rathjen, [Executive Dean of the Faculty of Sciences at the University of Adelaide], explains.

"They're to do with things like the fact that we have to learn how to grow lots and lots of the cells, probably billions of the cells.

"Once we've learnt how to grow them, we've then got to learn how to control their differentiation, that is, how do we turn the stem cells into the kind of cell that we want to transplant.

"And there's another very important limitation there, which is that the embryonic stem cells themselves are carcinogenic. That is, if you transplant them, you give rise to a particular kind of cancer.

"And then the final thing, and this is probably the greatest single hurdle, we need to find a way to overcome the immuno-rejection barrier, that is if you transplant cells into someone's body, then most of the time they're going to reject those cells as foreign...."