Multipotent Stem CellsAdult Stem CellsCell DifferentiationStem CellsStem Cell TransplantationMesenchymal Stromal CellsHematopoietic Stem CellsEmbryonic Stem CellsBone Marrow CellsCells, CulturedCell LineageCell- and Tissue-Based TherapyOctamer Transcription Factor-3Cell ProliferationNeural Stem CellsHematopoietic Stem Cell TransplantationAntigens, CD34Pluripotent Stem CellsStem Cell NicheColony-Forming Units AssayImmunohistochemistryStem Cell FactorHematopoiesis