RUNX1 and myelodysplastic syndrome: While MDS can occur from alterations in over a hundred genes, mutations in only six genes account for the majority of MDS cases: TET2, ASXL1, DNMT3A, the splicing factor 3b, subunit 1 (SF3B1), the serine and arginine-rich splicing factor 2 (SRSF2) and the RUNX family transcription factor 1 (RUNX1) [6,26,29].