Stem cell plasticity: Validation versus valedictory

Abstract

The field of stem cell plasticity, by which most commentators and investigators mean plasticity of adult stem cells, was opened to great fanfare with the publication of three papers in Science in the last 2 years of the prior millennium. This trio, taken together, was trumpeted by Science as the Breakthrough of the Year for 1999 and showed that stem cells deriving from one organ were not only not restricted to producing cells of that organ (so, e.g., marrow-derived cells could become skeletal muscle) but were also not restricted to their embryonic germ layer of origin (neural stem cells produced blood and marrowderived stem cells produced liver) [1-3]. © 2009 Springer Berlin Heidelberg.