JAK2 and myelofibrosis: Moreover, loss of Ezh2 accelerates the development of myelofibrosis and decreases survival in Jak2-V617F–driven MPN (Sashida et al., 2016; Shimizu et al., 2016; Yang et al., 2016) and Runx1 mutated MDS (Sashida et al., 2014), identifying EZH2 as a tumor suppressor.