Contribution to hematopoiesis of the IV and IB graft remained constant over time with the IV graft predominating. Peripheral blood samples were analyzed by flow cytometry at serial time points up to a year following transplantation to assess the relative contribution of each graft to hematopoiesis over time. Graphs represent the percentage contribution of GFP⁺ or YFP⁺/% GFP⁺ +YFP⁺ marked cells. Each animal had different a overall marking level due to differing transduction efficiency and differing endogenous recovery.