へへへ。
Abstract
Mature adult tissues contain stem cells that express many genes normally associated with the early stage of embryonic development, when maintained in appropriate environments. Cells procured from adult tissues representative of the three germ layers (spinal cord, muscle, and lung), each exhibiting the potential to mature into cells representative of all three germ layers. Cells isolated from adult tissues of different germ layer origin were propagated as nonadherent clusters or spheres that were composed of heterogeneous populations of cells.