Abstract: Traditionally, stem cells in adult tissues were believed to be restricted in their differentiation potential and limited to generate the types of cell present in the tissue in which the stem cell resides. Recently, however, many studies indicate that stem cells may display a broader differentiation potential, termed plasticity or transdifferentiation, than what was previously thought. But the validity of this understanding has been challenged by some investigators. In this review, the authors present some standpoints on stem cell plasticity and discuss some phenomena of stem cell plasticity observed on animal models those have been generally accepted currently.

Key words: stem cells, plasticity, transdifferentiation, review