Somatic mutations in TET2 are frequently observed in various myeloid malignancies, including myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), and MDS/MPN overlap syndromes, including chronic myelomonocytic leukemia (CMML), acute myeloid leukemia (AML), and secondary AML (sAML) [95]. The gene discussed is TET2; the disease is myeloproliferative neoplasm.