Stem cells can halt ageing - and even prolong lifespans up to three times, scientists say.
An experiment proved that a single injection of stem cells could make mice live three times as long.
The injection also made the mice grow bigger and stronger.
Scientists think that studying the proteins within stem cells might hold the key to injections that offer a 'shot of youthful vigour' to human beings.
That's big news. But will it apply to humans? And will there be undesirable side effects like cancer? To read more, click here.