C/EBPα accelerates G-CSF–induced granulocytic differentiation of 32Dcl3 cells. 32Dcl3 cells were retrovirally infected with wild-type C/EBPα (p42) or the empty vector MigR1. Morphology of GFP-positive cells was assessed by May-Grünwald/Giemsa staining of cytospin preparations at day 0 (left panels) and at day 3 (middle and right panels) from liquid cultures supplemented with the indicated cytokines. Representative of 3 different experiments. Original magnification, × 40.