Activating mutations in EZH2 have been observed in malignant B cell lymphomas [82,83]; however, loss of function mutations in EZH2 are frequently identified in patients with myelodysplastic syndrome (MDS) and MF [84] and loss of function is associated with drug resistance and adverse clinical outcome in hematologic malignancies [85,86,87]. The gene discussed is EZH2; the disease is hematologic disorder.