TET2 mutations are commonly identified in myeloid and lymphoid malignancies and are amongst themost recurrently acquired mutations identified in patients suffering from chronic myelomonocytic leukaemia (CMML, 50–60%), AML (~20%), and myelodysplastic syndromes (MDS, ~20%) [6–8]. This evidence concerns the gene TET2 and chronic myelomonocytic leukemia.