Cbfβ-SMMHC reduces expression of B lineage–specific factors. Relative expression levels of B lineage–specific transcripts Cd79a (mb-1), Igll1 (lambda5), VpreB1, and Blk in control or Cbfβ-SMMHC restored CLPs analyzed by qRT-PCR. Shown are mean plus or minus SD (n = 3; ** P < .01; *** P < .001) from 3 to 5 independent sorting experiments, each performed by duplicate.