Cell type distribution of Neo and NF-YA DN–infected BM cells treated with (A) IL-3 alone or (B) MCSF plus IL-6 (100 ng/mL).

Neo-resistant colonies were removed by pipet from the methylcellulose and used for cytospin smears. Morphologic differentiation was determined by counting at least 300 cells on May-Grünwald Giemsa–stained cytospin smears and scoring the proportion of immature blast cells, intermediate monocytes (A,B), intermediate granulocytes (A), mature granulocytes (A), and mature macrophages (A,B) determined as detailed in “Materials and methods.” Percentage of cells expressing the macrophages specific cell surface marker F4/80 was determined by FACS analysis as described in “Materials and methods.” Values are averages of 3 independent experiments, and SDs are indicated. The SDs of NF-YA DN–infected BM treated with IL-3 for mature cells, and Neo–infected BM treated with MCSF plus IL-6 for both mature and intermediate cells are too small to be seen.