Aging and TOR: interwoven in the fabric of life.

Longstanding results with calorie and growth factor restriction plus recent results with the first interventional drug suggest that retarding the pace of aging to improve the quality of life of older people is at hand. The biological system targeted by these approaches is the target of rapamycin (TOR), which is central for cellular responses to a variety of stimuli including stressors, growth factors, and nutrients and energy states. That the life-extending response to reducing its activity is highly conserved from yeast to mammals is consistent with the evolution of aging as a strategy to preserve reproductive potential of young cells and animals.