KITLG and Increased total leukocyte count: We believe however that our data are of interest for a better understanding of our in vivo transduction approach and of the fate of HSCs after mobilization with different drugs: (1) G-SCF alone and in combination triggered pronounced leukocytosis; (2) our in vivo HSC marking approach indicates that AMD3100 and BIO5192 results in more efficient in vivo transduction of HSCs/progenitors that return to the bone marrow; (3) at week 8 after in vivo transduction, HDAd genomes can still exist in episomal form in HSCs; and (4) SB100x-mediated integration requires an effect triggered by G-CSF.