TET2 and myelodysplastic syndrome: Approximately, 80% of patients with MDS have one or more oncogenic driver mutations (SF3B1~24%, TET2~22%, SRSF2~15% and ASXL1~15%).4 In a large study (n=738), Papaemmanuil et al.4 demonstrated that driver mutations had an equivalent prognostic significance and LFS steadily declined as the number of driver mutations increased.