Expression of CBFβ-MYH11 in primary human CD34⁺ cells leads to long-term proliferation. (A-C) Transduced (nonsorted) human CD34⁺ cells were expanded in KTF36 media, counted weekly by trypan blue dye exclusion, and stained and analyzed by flow cytometry. (A) GFP expression, (B) CD34 expression, and (C) total cell number are shown. A transduction with the related oncogene AML1-ETO (AE) is shown as a comparison for cell growth during the first 20 weeks. The error bars represent the SD from 3 separate experiments. (D) Southern blot of long-term cultures indicating the clonal nature of the long-term CM cultures. GFP was used as the probe. W indicates weeks in culture.