The C/EBP-ϵ isoforms differentially induce or inhibit eosinophil gene transcription. Analysis by real-time RT-Q-PCR. CD34⁺ CB cells were transduced 3 times with the retroviral vectors encoding the 3 C/EBP-ϵ isoforms and empty retroviral vector control over a period of 72 hours, double CD34⁺GFP⁺ progenitors sorted by FACS, grown for 14 days in suspension cultures supplemented with IL-3 + IL-5 to drive eosinophil differentiation (as in Figure 6), and total RNA prepared and reverse-transcribed to cDNA. The expression of genes encoding eosinophil secondary granule proteins, including major basic protein-1 (MBP1), eosinophil-derived neurotoxin/ribonuclease-2 (EDN, RNS2), and eosinophil peroxidase (EPX) (A), the soluble and transmembrane alternative RNA splice forms of the eosinophil-specific IL-5 receptor α (IL-5Rα) subunit (B), and GATA-1 and β-globin (C) were analyzed by RT-Q-PCR. The mean cDNA expression levels relative to the expression of the β2M input control in each sample amplified at the same time are plotted (± SD) for 3 independent experiments analyzed in triplicate. Statistically significant differences are shown for comparisons between means using 1-way ANOVA and LSD (*P ≤ .05, ***P ≤ .001).