RUNX1 and myelodysplastic syndrome: Loss-of-function missense or nonsense mutations involving the RUNX1 gene are common in MDS/ AML, occurring in 10–15% of patients and associated with inferior prognosis after treatment with hypomethylating agents and induction chemotherapy.(27, 35, 36) The poor outcomes are in part due to the lack of an approved therapy targeting RUNX1.