Id2 expression is deregulated in Gfi-1^−/− mice. (A) CD4⁻CD8⁻, CD4⁺CD8⁺, and CD4⁺CD8⁻ and CD4⁻CD8⁺ T lymphocytes were purified from Gfi-1^+/+ and Gfi-1^−/− thymuses by sorting. RNA was harvested from each population and analyzed for Id2 mRNA expression levels by real-time qRT-PCR. (B) B220⁺CD43⁻ and B220⁺CD43⁺ B lymphocytes were purified from Gfi-1^+/+ and Gfi-1^−/− bone marrows by sorting. RNA was harvested from each population and analyzed for Id2 mRNA expression levels by real-time qRT-PCR. (C) LSKs, CMPs, GMPs, and MEPs were purified from Gfi-1^+/+ and Gfi-1^−/− mice by multicolor-based sorting. RNA was harvested from LSK, CMP, GMP, and MEP, and analyzed for Id2 mRNA expression levels by real-time qRT-PCR. All samples were normalized to GAPDH. *P < .05 in 2-sided t test. Three independent experiments were performed.