The loss of EZH2 in JAK2 V617F hematopoietic cells was shown to reduce H3K27me3 levels with an increase in H3K27 acetylation and the resulting activation of PRC2 target genes including High Mobility Group AT-Hook 2 (HMGA2), an oncogene previously implicated in PMF and other myeloid neoplasms [66,67]. The gene discussed is HMGA2; the disease is myeloid neoplasm.