Disappearance of EGFP/EYFP-marked cells after transplantation. Shown for each of the 5 animals that underwent transplantation in this study are the percent of peripheral blood leukocytes positive for transgene as measured by flow cytometry (closed symbols) and by real-time PCR (open symbols). Squares indicate EYFP marking, whereas circles indicate EGFP marking. See Table 1 for vector details.