United States researchers have come up with a novel use for men's testicles, which they say are a rich source of stem cells and so could be transformed into a wide range of tissue types to help fight disease.
The scientists say they have managed to isolate stem cells from the testes of male mice, extract them and reprogram them into blood vessels, heart cells and tissue.
They say if the results can be reproduced in humans, the technology could help get around the ethical concerns associated with the use of embryonic stem cells and could be used to help treat Parkinson's, heart disease, strokes and cancer.
It has taken years for Shahin Rafii from Weill Cornell Medical College in New York to get to this point, but he says he has persevered because the testes provide such a potentially rich source of stem cells.
"Testes are designed to generate a lot of sperm and they have these germ cells," he said.
"So germ cells are designed also in a way to give us two different tissues as well so we were able to get a germ cell from testes and instruct them to become other tissues."
Dr Rafii says the results will be transferable to humans.
"It can easily be applied to a human in near future," he said.
He says it will not be difficult to find subjects.
"If I had end stage heart disease, I would think, take all my testes, all right? So it is a no-brainer," he said.
Dr Rafii's research has been published in the journal Nature.
The executive director of the Prince of Wales Medical Research Institute in Sydney, Peter Schofield, says while the work is promising it will be some time before the results could be reproduced in humans.
"I think there's still quite a bit of experimental work to be done," he said.
"The mouse experiments used a number of techniques which are possible in mouse embryology but would not in any way be translatable to potential human treatment today.
"But the important thing is that the experiments showed was that it was possible."
Professor Schofield says there is a high level of interest in creating stem cells that are not from embryos.
"Certainly the comments that came out from the researchers' labs in the United States perhaps are a little bit over-selling around the potential benefits of adult versus embryonic stem cells," he said.
"I guess the situation here in Australia is that both of them are now permitted under various strong licensing regimes and the technology that delivers the clinical benefits will obviously be the one that works.
"This is really important research because it shows that there is another possible way of reprogramming adult stem cells. In the mouse it shows that those cells were able to form important other organs.
"There's still a lot of steps before that could be done in a human situation, but the fact that it has been done is both very exciting and offers a lot of promise."
So it is a possible breakthrough, albeit somewhere down the track, for men. But Dr Rafii says women need not give up hope.
"In women also this stem cell exists but the number is very, very low and we hope that eventually we can be able to get these stem cells from their ovaries as well," he said.
"Also another point - some men can give stem cells to compatible, genetically compatible females so it still can be applied for women as well."