Reconstitution of hematopoiesis with GFP-marked PB cells in lethally irradiated animals transplanted with GFP-transduced BM. Flow cytometric analysis of GFP expression in RBCs, platelets, and leukocytes was performed as described in Materials and Methods. For the white blood cell (WBC) panel, very high-level GFP fluorescence in expressing cells necessitated analysis using lower fluorescence amplification for all the WBC samples. The profiles of representative animals transplanted with marrow transduced with the control CD24 vector, the MGirL22Y vector, or an equal number of MGirL22Y- and CD24-transduced marrow cells 4 weeks posttransplantation are shown as indicated. The proportion of GFP-positive cells within each respective population is indicated.