32D cells, insert-less infected cells (32D/LXSN), and cells infected with the c-myb transactivation domain in antisense orientation (32D/mybTAS) were grown for 5 days in the presence of G-CSF (10% of U87MG conditioned medium). Cytospin smears were stained by May Grünwald-Giemsa and 100 cells were counted. Representative of three different experiments with similar results.