We report the clinicopathologic and molecular genetic features of 21 cases of myeloid neoplasms with double mutations in SF3B1 and PHF6, including 9 (43%) with myelodysplastic syndrome, 5 (24%) with acute myeloid leukemia, 4 (19%) with myeloproliferative neoplasms, and 3 (14%) with myelodysplastic/myeloproliferative neoplasms. This evidence concerns the gene PHF6 and myelodysplastic syndrome.