The problem is cancer caused as a side effect.
I also saw most of an SBS Insight program about therapeutic cloning and stem cell research a few weeks ago. It was interesting to see at least some medical experts expressing scepticism of stem cell treatment:
JENNY BROCKIE: Jack Martin, you're former director of St Vincent's Institute of Medical Research. Do you share this optimism about stem cell research?
JACK MARTIN, FMR. PROF. OF MEDICINE, MELBOURNE UNIVERSITY: No, I have to say I don't. And I would take issue with quite a number of things that Elizabeth Finkel has just said. She's implied that there has been proof of concept of efficacy of embryonic stem cell therapy in a number of diseases and mentioned Parkinson's disease, spinal cord injury and diabetes, and that is absolutely untrue. There are temporary and partial improvements in chemically induced Parkinson's disease in rodents and in a couple of monkey studies, and in no case has this been prolonged and in no case has it been a long enough.. It's either been associated with a serious complication of cancer teratoma formation or it's not been carried out for long enough to determine whether that's been avoided or not.Of course, there were others present who were much more optimistic than this.