RUNX1 and myelodysplastic syndrome: Changes in VAFs between the initial and follow-up biopsy for individual patients are shown for two commonly mutated genes (SRSF2 and RUNX1) in Fig. 1E, F. SRSF2 showed no clear trend in VAFs in MDS (median 44% (first) vs. 45% (follow-up)) or MDS-IB/EB cases (median 38% vs. 31%).