Fusion gene ND13 perturbs the differentiation and proliferative potential of primitive myeloid progenitors, and its activity is dependent on the HOXD13 homeodomain and NUP98 portion. (A) Total number of d12 CFU-S derived from 5000 FACS-purified control GFP or ND13-transduced injected BM cells (mean ± SD, n = 2). (B) Lineage distribution of GFP⁺ d12 CFU-S–derived transduced cells. 2 × 10⁴ cells recovered after infection were injected without selection into irradiated mice, and single spleen cell suspensions (2 spleens/construct) were analyzed by FACS 12 days later for GFP and lineage-specific marker expression (n = 2; representative experiment shown). □ indicates GFP; ▦, ND13. (C) Expression of FLAG-tagged ND13 wild-type and mutant constructs in nuclear extracts of transfected 293T cells detected by Western blot using an anti-FLAG monoclonal antibody. (D) Total number of d12 CFU-S colonies derived per culture initiated with 1 × 10⁶ cells transduced with the GFP, ND13, and mutant viruses after 1 week in liquid culture. Yields for TR-HOXD13 and ND13-N51S were significantly different from those for ND13 (P < .03) (mean ± SD; n = 3 for all except TR-HOXD13 [n = 2]).