EP300 and myelodysplastic syndrome: The loss of p300 increased Myb expression in both Asxl1+/– and Srsf2P95H HSPCs (Figure 5, B and D), highlighting the consistent upregulation of Myb in the effect of p300 loss on MDS models driven by an array of mutations, which represent up to 70% of the genetic abnormalities found in MDS patients.