TET2 and myelodysplastic syndrome: In addition, the MDS classification that was available did not include specific subtypes of MDS associated with mutations in the splicing genes (for example, U2AF1 and SRSF2 genes which are associated with an unfavorable prognosis) or in epigenetic modifiers (such as ASXL1, TET2, DNMT3A, etc.)were associated with poor outcomes.