Stem cells are cells that have the remarkable potential to develop into many different cell types in the body. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells for as long as the person or animal is still alive.
The most eagerly anticipated therapeutic use for stem cells is regenerative medicine. Biologists dream of the day they can take a stem cell and create any of the body’s cell types, producing pancreas or liver tissue that doctors could use to aid a failing organ. But to realize that dream, scientists must first understand the forces operating in stem cells — what makes some stem cells stay stem cells, while others grow into brain, liver, and skin cells?
Technology review magazine from MIT has a nice article on how scientists are learning how to control the two unique properties of stem cells.