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