The key gene that keeps embryonic stem cells in a state of youthful immortality has been discovered.

The breakthrough may one day contribute to turning ordinary adult cells into those with the properties of human ESCs. This would end the need to destroy embryos to harvest the cells for new medical treatments.

ESCs are unique as they are "pluripotent" - capable of differentiating into the different cells in the body - and hold great potential for treating damaged or diseased organs. But until now scientists did not know how a stem cell renews itself or develops into an new kind of cell.