IRF-8 expression increases during thecommon myeloid progenitorto CDP transition. Microarray analysis was carried out on double-sorted common myeloid progenitors (CMPs) and CDPs from BM. (A) Common myeloid progenitors were lineage (Lin)⁻c-kit^hiSca-1⁻CD16/32⁻CD34⁺ Flk2⁺CD115⁻ and CDP were were Lin⁻c-kit^intermediateSca-1⁻CD16/32⁻CD34⁺Flk2⁺CD115⁺. (B) In vitro differentiation of common myeloid progenitors and CDPs. Cells were cultured for 7 days with IL-3, GM-CSF, Flt3 ligand, and stem cell factor (all 10 ng/mL). DC (CD11c⁺Gr-1⁻) and neutrophil (CD11c⁻Gr-1⁺) potential was analyzed by flow cytometry. (C) Heat map of microarray data showing selected transcription factors that were differentially regulated at least 5-fold between the common myeloid progenitor and CDP subsets. (D) Quantitative RT-PCR analysis of IRF-8 in double-sorted LMPP, common myeloid progenitor, GMP, and CDP. Data represent 3 or 6 independent sorts for GMP and CDP or LMPP and common myeloid progenitor, respectively, analyzed in 3 separate assays; **P < .05.