The behavior of progenitors isolated from single CB units. Lin^neg ALDH^br CD34⁺ progenitors were isolated from a single CB unit and transplanted into 9 NSγ mice at different cell doses. The peripheral blood of those mice was monitored for CD45⁺ cells 7 weeks after transplantation (A) and for CD45⁺ CD3⁺ T cells at 19 weeks after transplantation (B). Twenty-one weeks after transplantation, the mice were killed, and their levels of human hematopoietic chimerism was analyzed in both the peripheral blood (C) and bone marrow (D).