Engraftment of transduced baboon marrow cells in NOD/SCID mice. Displayed are examples from the 3 groups of mice that underwent autologous transplantation in parallel with baboons. (Left) mock-transduced cells; (middle) PG13; (right) Phoenix-GALV-transduced cells. (B) Engraftment with baboon SCRs is stable over 12 weeks. Two mice were observed for 12 weeks before bone marrow was harvested and analyzed. Neither the percentage of engrafted baboon cells nor transgene expression is markedly different than at 6 weeks after transplantation.