Fig. 1.

DNA methylation and hematopoietic development. (A) Schematic of the ‘classical’ view of hematopoiesis, where starting from a HSC, the whole blood cell population is formed in every subsequent step (binary bifurcation points). Epigenetics plays an important role in regulating both the myeloid and lymphoid lineages. Genes with key roles in HSC self‐renewal and pluripotency (termed stemness genes in the picture) are preferentially expressed at early stages of the process. On the contrary, as the different lineages are selected, the respective lineage‐specific genes are expressed accordingly. (B) In hematological malignancies, the epigenetic patterns present under homeostatic control become aberrant and the cells may suffer malignant transformations in every stage of the process. We illustrate schematically the main consequences of key effector methylation enzymes' malfunction and their impact in self‐renewal, lineage bias, and differentiation, along with some examples of the resulting up‐ or downregulated target genes.