Clone wars: is the medical miracle of the century a cure or a curse?
Imagine a world where undergoing a heart transplant merely involves making a hospital appointment after checking to see if your new heart is ready.
Parkinson's disease is a thing of the past. Multiple sclerosis, motor neurone disease and diabetes are easily treated and childless couples can avoid costly IVF treatment by arranging to have a baby created from their own cells.
That world has moved a step closer after scientists revealed that human cloning had been used to create embryonic stem cells from which new tissue, identical to the donor's own cells, could be grown.
But while the possibilities for the new technology are endless, so too are the ethical questions.
Not only does it pave the way for human cloning, it also involves destroying a human embryo so that the cells can be harvested.
A team based at the Oregon Health and Science University in Portland, led by Shoukhrat Mitalipov, managed to clone one embryonic stem cell using two human eggs.
The results had no abnormalities, showed normal gene activity and were capable of being turned into specialised cell types that could be used to replace damaged tissue, the team said.
The advance would make the method "practical for widespread therapeutic use", it added.
The development was hailed as a major boost for those needing organ transplants, heart-failure patients and people suffering from a range of debilitating medical conditions.
But not everyone is happy, with warnings that science has moved us a step closer to the dystopian world depicted by Kazuo Ishiguro in his 2005 novel Never Let Me Go.
It tells the story of 'donors' being cloned solely for organ harvest, isolated by society and doomed to an early death – referred to as 'completion'.
It's not the first time that similar warnings have been sounded. In 1997, scientists announced they had successfully cloned a sheep named Dolly, and there were hysterical outpourings of concern about the possibility of a new Hitler or Saddam Hussein being created by rogue scientists.
Despite this controversy, and the fact that research in this area is continuing all the time, there is currently no law in Ireland governing assisted human reproduction, or cloning.
The Department of Health says that proposals on the "complex area" were being considered, adding that Medical Council rules classed the creation of "new forms of life" for experimental purposes as professional misconduct.
"The Medical Council guidelines do not cover non-medical researchers," says a Department spokeswoman.
So what's to stop a scientist from setting up a lab and attempting to create a human clone, or grow hearts, lungs and a range of body parts using embryonic stem cells?
"At the moment the legal status is unclear," says Professor Martin Clynes, director of the National Institute for Cellular Biotechnology at Dublin City University.
"There should be legislation around all this. In principle, if you had a lot of money you could do this. There would be some medical regulations, so whether you could do the whole thing is unclear.
"I would have ethical issues there because you've decided to bring that embryo into existence just to destroy it. That's a road I don't think we should take."
There are alternative ways of getting stem cells – a technique is being developed to use adult cells to create stem cells and new tissue. Stem cells can also be harvested from the umbilical cord. But not everyone agrees that research using embryos should be banned.
Professor John Harris, director of Manchester University's Institute for Science, Ethics and Innovation, believes there are benefits.
"It could be used in medically helpful ways," he told a British newspaper. "If a couple find they are carriers of harmful, possibly fatal recessive genetic illnesses, there is a one-in-four chance they will produce a child who will die of that condition. That is a big risk.
"An alternative would be to clone one of the parents. If you did that, then you would know you were producing a child who would be unaffected by that illness in later life."
The issue of cloning is tied up with the difficult ethical issues also associated with the current abortion debate, dealing with questions around when life begins, whether embryos have rights or if they are just a collection of cells.
Two reports, one going back to 2005, have already suggested practical and conservative guidelines for legislation, which would give scientists certainty and address ethical concerns about producing embryos for research.
But the prospect of a human clone is still some way away, according to Professor Clynes.
"A lot of research probably will happen, but I couldn't say there'd be something in five or 50 years; it's still at quite an early stage."