Complete hematopoietic development in NSγ mice. After long-term transplantation assays (≥ 19 weeks), human hematopoietic engraftment was analyzed in 32 NSγ mice. In total, 27 mice had detectable human hematopoietic cells, and the levels of chimerism were dose dependent (A). Complete hematopoietic development was documented in 16 NSγ mice, as defined by human T-cell development in multiple tissues. These mice exhibited high levels of chimerism and were predominately mice that had been transplanted with high doses of Lin^neg ALDH^br CD34⁺ cells (B). The human CD45⁺ cells within the bone marrow of these mice included CD19⁺ B cells (C), CD3⁺ T cells (C-E), CD56⁺ NK cells (E), CD13⁺ myeloid cells, and CD34⁺ progenitors (F). The CD3⁺ cells coexpressed canonical T-cell antigens (CD8; D). Panels G-J: Human CD34 progenitors were enriched from 10 primary NSγ transplant recipients to perform secondary transplantation assays. Initially, lineage-committed murine cells were depleted using immunomagnetic beads (not shown). After that depletion, the resulting fractions were enriched with human CD45⁺ cells that contained high percentages of CD45⁺ CD34^neg cells (G). The progenitor cells were further enriched after the depletion of mature human cells. Human CD19⁺ and CD3⁺ cells were removed entirely (not shown). The CD34⁺ cells were CD45^dim as expected for progenitors (panel H). Human hematopoiesis was established in secondary NSγ recipients at 6 (I) or 12 weeks (J) after transplantation.