TET2 and myeloproliferative neoplasm: In contrast, TET2 is clearly a tumor suppressor in all hematopoietic cell types reported so far, since deletions and loss-of-function mutations in the TET2 gene are strongly associated with myelodysplastic syndromes, myeloproliferative neoplasms, and myeloid leukemias as well as lymphoid malignancies (126, 127).