Levels of vector-expressing peripheral blood cells in animals 12 weeks after transplantation with GATA-2irGFP or control irGFP vector transduced bone marrow cells. The percentages of red blood cells (RBC), platelets (PLT), and leukocytes (WBC) expressing GFP in the peripheral blood of 10 animals transplanted with the indicated cells were determined by flow cytometry as described in Materials and Methods. The data represent the mean ± standard error of the percentage of GFP⁺ cells in each blood lineage for each group. The percentages of GFP⁺ cells in each cell subset in the two groups of animals were all statistically significantly different (P < .0004 or less) from each other.