Trib1 regulates C/EPBα levels to control eosinophil identity. (A) C/EBPα immunoblot analysis of sorted neutrophils (CD11b⁺Ly6G⁺SiglecF⁻F4/80⁻), and CCR3⁻ and CCR3⁺ eosinophils (CD11b⁺SiglecF⁺F4/80⁺) from the BM of Trib1^+/+ and Trib1^ΔHSC mice; β-actin is the loading control. Representative of 2 experiments. (B) C/EBPα immunoblot analysis of sorted GFP⁺ BM cells from mice transplanted with shRNA-transduced BM cells, 9 weeks after transplantation with β-actin as a loading control. shLuc control targets firefly luciferase; shB9 and shB11 target Cebpa. Sorted GFP⁺ cells from 3 representative mice are shown. Representative of 2 experiments. (C) Percentage of GFP⁺ cells expressing control or C/EBPα shRNAs B9 or B11 cells expressing SiglecF with surface expression of SiglecF. Representative of 2 experiments. (D) Mean fluorescence intensity (MFI) of Ly6G expression on BM eosinophils (GFP⁺CD11b⁺SiglecF⁺) expressing either control or C/EBPα shRNAs B9 or B11; n = 4-5 mice per group, representative of 2 experiments. **P < .0052, 2-way analysis of variance with multiple comparisons. Frequencies and error bars are mean ± SEM of GFP⁺ cells.