"unity" biotechnology: the problematic pursuit of immortality in the midst of profound inequality...,

npr |  Mice were much healthier and lived about 25 percent longer when scientists killed off a certain kind of cell that accumulates in the body with age.

What's more, the mice didn't seem to suffer any ill effects from losing their so-called senescent cells.

These are cells that have stopped dividing, though not necessarily because the cells themselves are old. "It's a normal cell that experienced an unusual amount of stress, and it decided to stop dividing," says Jan van Deursen, who studies senescent cells at the Mayo Clinic College of Medicine in Rochester, Minn.

Older creatures have a lot more of these cells than young 'uns. And even though the cells aren't dividing, they do keep busy — they secrete a mixture of chemicals that can trigger inflammation, which seems to be involved in just about every major age-related disease.