HDAC1 and leukemia: Interestingly, we observed that Hdac1Δ/Δ; Hdac2Δ/Δ Eμ-myc mice had significantly lower PBL counts, compared to control Hdac1+/+; Hdac2+/+ Eμ-myc mice, and hence reduced leukemia burdens (Fig. 3C).