HOXB3 and acute myeloid leukemia: Notably, among 30 differentially methylated PcG target developmental genes, 29 (e.g., HOXA6, HOXB3, and MEIS1) were hypomethylated in DNMT3A mutant AML (R882: major mutation) relative to DNMT3A WT AML, suggesting that inactivating DNMT3A mutation causes defects in epigenetic repression of PcG target developmental genes (Fig. 6c, d).