DNMT3A and leukemia: As many genes related to HSC self-renewal or dysregulated in leukemia (e.g., HoxA9, Meis1, and Evi1) were under the control of large undermethylated domains termed “canyons” whose boundaries were eroded in the absence of DNMT3A [37], DNMT3A-mediated methylation of canyon borders may also contribute to the suppression of transformation.