By now, most people are probably aware of the therapeutic value of stem cells, as they can become any other type of cell in the human body. One of their main duties, in fact, is to replace those other cells as they degrade. Once people reach an advanced age, however, even the stem cells themselves start to get old and nonfunctional - when the cells that are supposed to replace the other cells can't do their job anymore, age-related tissue problems start occurring. A team of researchers from the Buck Institute for Research on Aging in collaboration with the Georgia Institute of Technology, however, may be on the way to solving that problem. They have succeeded in reversing the aging process in human adult stem cells.