DNMT3A and myelodysplastic syndrome: Because DNMT3A mutation was closely associated with SF3B1 mutation, a good prognostic factor in MDS patients [35, 36], we divided the whole cohort to two subgroups, SF3B1-mutated and SF3B1-wild type, to evaluate the prognostic significance of DNMT3A mutation independent of SF3B1 mutation.