Low-density mononuclear BM cells were depleted of lineage-positive (lin+) cells as described previously (Milsom et al. Blood, (2009). After antibody staining, lin–, Sca-1+, c-Kit+ (LSK) cells were isolated by flow sorting. LSK cells were prestimulated for 48 hours, after which the cells were transduced with a vector expressing PIDK or Mieg3 empty control vector. 48 hours later, % transduction was determined. Cells were then cultured in 10% IMDM + cytokines for an additional 12 days. The percentage of GFP+ cells in culture was determined at days 2, 5, 7, 10, and 12 post-transduction.