Gene marking levels in peripheral blood cells of monkeys that received HIV-based lentiviral transduced marrow stem cells. (A) The vector provirus genomes in PB from monkeys J02043, J02370, and T04228 were determined by Taqman PCR relative to a control cell line with a single integrated lentiviral vector to determine the average proviral vector copy number. The average copy number from all dates is indicated in parentheses. (B) Southern blot analysis confirms high-level marking in all 3 monkeys. Vertical lines indicate repositioned gel lanes.