DNMT3A and B-cell chronic lymphocytic leukemia: Consistently with possible roles of Dnmt3a and Dnmt3b in CLL development we have previously reported that conditional inactivation of Dnmt3a in hematopoietic stem cells and progenitors in EμSRα-tTA;Teto-Cre;Dnmt3afl/fl;Rosa26 LOXPEGFP/EGFP (Dnmt3aΔ/Δ) mice resulted in the development of chronic lymphocytic leukemia (CLL) around 1 year of age and is accelerated when Dnmt3b is deleted as well9.