TET2 mutations and loss of function have been reported in myeloid malignancies, including myeloproliferative neoplasm (MPN), acute myeloid leukemia (AML), secondary AML, myelodysplastic syndrome (MDS), and chronic myelomonocytic leukemia (CMML) [339, 340, 341, 342, 343, 344, 345]. This evidence concerns the gene TET2 and chronic myelomonocytic leukemia.