Cebpa/EYFP expression is found in a significant fraction of Sca-1^low CD34⁺ LSK cells, whereas it is rarely expressed in LT-HSCs. (A) Analysis of the percentage of Cebpa/EYFP⁺ cells in the CD34⁻ and CD34⁺ LSK compartment of adult murine bone marrow. (B) Percentage of Cebpa/EYFP⁺ cells among LT-HSCs (CD150⁺CD48⁻). (C) Percentage of Cebpa/EYFP⁺ cells in FL LSK cells of a Cebpa^cre/+ R26 EYFP embryo on day E14.5. (D) Analysis of Sca-1 expression levels in the LSK population reveals that the majority of Cebpa/EYFP⁺ LSK cells resides among the Sca-1^low fraction. (E) Analysis of Cebpa/EYFP expression in CMP, GMP, and MEP. (F) Cebpa/EYFP expression in CLP. (G) Summary of Cebpa/EYFP⁺ cells in hematopoietic compartments. Within the CD34⁺ LSK population, a comparable percentage of Cebpa/EYFP⁺ cells was found in the Flt3⁺ and Flt3⁻ fraction (12.1% vs 14.4%; supplemental Figure 3B; supplemental Table 4).