Besides SM, loss-of-function mutations in TET2 as well as alterations in other genes mentioned above have been also reported in a variety of hematological malignancies, including acute myeloid leukemias (AMLs), chronic myelomonocytic leukemia (CMML), myeloproliferative neoplasms (MPNs), myelodysplastic syndromes (MDS) and lymphoid malignancies [20–24]. The gene discussed is TET2; the disease is chronic myelomonocytic leukemia.