NRAS and myelodysplastic syndrome: However, RUNX1, EZH2, NF1 and KRAS/NRAS mutations had significant effects on OS in our prognostic model, which coincided with the previous study (19) showing that RUNX1, EZH2 and NF1 mutations had significant effects on OS in SF3B1-mutant MDS patients within the IWG dataset.