On the contrary, loss-of-function EZH2 mutations have been observed more frequently in MDSs, atypical chronic myelogenous leukemia (CML), myelofibrosis, and T-cell acute lymphoblastic leukemia (T-ALL) [12], where they have been associated with a worse prognosis [24]. The gene discussed is EZH2; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.