You might recall the research by Cuervo's group demonstrating a restoration of youthful levels of autophagy in mouse livers. We know that autophagy is important to longevity: it clears out biochemical junk and damaged cellular components, of which the most important are probably damaged mitochondria. Furthermore, autophagy is enhanced by calorie restriction, and appears necessary for the longevity benefits of calorie restriction to take place. The most interesting tidbit from this ABC News article is that it looks like Cuervo's method of restoring autophagy levels does in fact increase life span (as measured by survival rates at various ages) in mice: "In experiments, livers in genetically modified mice 22 to 26 months old, the equivalent of octogenarians in human years, cleaned blood as efficiently as those in animals a quarter their age. By contrast, the livers of normal mice in a control group began to fail. ... While her paper does not show increased survival rates among the mice, le Couteur, who has advised her recently on the research, says Cuervo does have data on improved survival rates which she intends to publish. He also says she is now working with pharmaceutical companies to identify drugs that will turn the receptors on, or make them more active. Cuervo believes maintaining efficient protein clearance may improve longevity and function in all the body's tissues."