Stem cells are unspecialized cells that have been defined in many different ways but they
have two important characteristics that distinguish them from other cells in the body. First,
they can replenish their numbers for long periods through cell division. Second, after
receiving certain chemical signals, they can produce, through asymmetric cell division, a
progeny that can differentiate or transform into specialized cells with specific functions, such
as heart, nerve or muscle. In recent years, stem cells have received much attention owing to …