GATA1 and erythroleukemia: Sequencing the epigenetic landscape of human erythroleukemia and functional in vitro and in vivo studies strongly proposes that different alterations ultimately converge to impaired GATA1 activity.9 The NSD1 gene is located on the long arm of chromosome 5, a region that is the most frequent target of cytogenetic alteration in erythroleukemia cells.10 It is, therefore, possible that reduced NSD1 activity (e.g. by deletion or point mutations) contributes to leukemogenesis by impairing GATA1 transactivation and erythroid differentiation.