Increased expansion of Smad4^−/− primitive hematopoietic cells transduced with HOXA9 or NUP98-HOXA9 in mice after transplantation. (A-D) FACS analysis of BM cells, 7 weeks after transplantation. Representative FACS data (left panel). The right panel displays a bar diagram, for Smad4^−/− (red bars) or Wt (blue bars) cells transduced with HOXA9 or NUP98-HOXA9 (data show mean ± SEM, n = 8 for each group, *P < .01 measured by Student unpaired t test). (A) FACS analysis showing engraftment of Wt (blue) and Smad4^−/− (red) cells transduced with HOXA9 or NUP98-HOXA9 (% of GFP⁺). (B) FACS analysis showing increased expansion of LK (c-Kit⁺ Sca-1⁻) and LSK cells (c-Kit⁺Sca-1⁺) in the Lin⁻ cell subset of BM from mice transplanted with Smad4^−/− cells transduced with HOXA9 or NUP98-HOXA9. (C) Percentage of LT-HSC, ST-HSC, and MPP among the population of LSK subset of cells from BM of mice transplanted with Wt (blue) or Smad4^−/− (red) HSPCs transduced with HOXA9 or NUP98-HOXA9. (D) FACS analysis showing increased percentage of cells in S phase among the population of LSK subset of cells from BM of mice transplanted with Smad4^−/− primitive hematopoietic cells transduced with HOXA9 or NUP98-HOXA9. (E) Ex vivo culture of BM cells showing that the frequency of cells that make a colony was markedly increased in BM from mice transplanted with Smad4^−/− HSPCs, compared with mice transplanted with Wt HSPCs. Samples were analyzed 7 weeks after transplantation.