Since then, the prevalence of EZH2 mutations, their association with deletions of the other allele, their pathogenic role [22], and negative clinical implications [9, 23] have been broadly studied in MDS/MPN cohorts where alterations of this gene are relatively frequent and often associated with mutations in ASXL1 (also a member of the Polycomb group of proteins), TET2, and RUNX1 [24]. This evidence concerns the gene RUNX1 and myeloproliferative neoplasm.