ASXL1 and myelodysplastic syndrome: Importantly, MDS/MPN patients with ASXL1 mutations have more severe anemia and higher proportions of early-stage erythroblasts compared to patients with WT ASXL1. Therefore, ASXL1 mutations may impair erythroid commitment and terminal differentiation, contributing to the refractory anemias experienced by MDS and MDS/MPN patients with ASXL1 mutations.