Engraftment and transgene expression levels in peripheral blood cells of monkeys that received lentivirally transduced stem cells from bone marrow using a 48-hour transduction protocol. Displayed for all 3 monkeys that underwent transplantation are the absolute neutrophil counts (A) and platelet counts (B) after transplantation. The solid line marks the interpolated time course of average cell numbers. The percentages of EGFP-expressing leukocytes detected by flow cytometry are shown for monkeys J02370 (C) and T04228 (D).