Juan Carlos Izpisúa Belmonte works at the Gene Expression Laboratory at San Diego's Salk Institute for Biological Studies applied a tool called reprogramming that took a mouse on its death bed and made it lively and active, according to technology review.
Reprogramming is a way to reset the body's epigenetic marks which are essentially chemical switches in a cell that determine which genes are turned on and off. If these marks are erased the cell can forget what type of cell it was and revert to a much more primitive and embryonic state. The concept could allow "aged" cells to be reverted back to be younger and more active.
Although these epigenetic modifications won't make a person or animal live forever, they can increase your life expectancy. Izpisúa Belmonte believes that this process could extend human life by another 30 to 50 years at least. He commented, "I think the kid that will be living to 130 is already with us."
The concept of extending human life does raise ethical questions, but the concept of cell rejuvenation is still far off. More limited versions of it though could be available within a few years, possibly preventing aging and increasing overall life expectancy.