Expression of Irf8, Pu.1, Ebf, Pax-5, and E2a in HSCs, CLPs, MPs, and various B-cell subsets. Each cell population was sort-purified from a pool of 5 to 6 mice. RNA was extracted and reverse transcribed. qPCR was used to quantitate Irf8 (A), Pu.1, Ebf, E2a, and Pax-5 (B) expression levels. Data are mean plus or minus SEM of 3 independent experiments. UD indicates undetectable.