CEBPA and precursor B-cell acute lymphoblastic leukemia: To decipher how large enhancer assemblies act during a cell fate conversion process we used a human B-ALL cell line (BLAER) containing an estrogen (E2) inducible CEBPA construct whose activation results in macrophage transdifferentiation within 7 days (Rapino et al, 2013) (Fig. 1A).