CFSE-labeled cell division history of CD34⁺ CD90⁺ after 9 days of culture. Cell division history of CD34⁺CD90⁺ exposed to 5azaD and TSA with cytokine cocktail (described in “Materials and methods”) after 5 and 9 days of culture labeled with CFSE. Each panel shows a representative flow cytometry profile for CFSE fluorescence intensity as a function of cell number for each day studied. (A) Uncultured marrow CD34⁺ cells. (B) CD34⁺CD90⁺ cells after 5 days of culture treated with 5azaD and TSA. (C) CD34⁺CD90⁺ cells after 9 days of culture treated with 5azaD and TSA. The number above each peak indicates the number of cell divisions undergone by cells within each peak of CFSE fluorescence.