EPO and myelodysplastic syndrome: Importantly, however, by using multivariable analysis that included serum EPO level and RBC transfusion volumes as variables, we showed that the presence of ASXL1 mutations besides EPO level was significantly associated with poor response to DA among the highly frequent (> 10%) gene mutations observed in this study such as those in SF3B1, TET2, SRSF2, ASXL1, and DNMT3A. Because MDS are heterogenous not only in morphology but also in molecular pathogenesis, it was difficult for less frequent gene mutations to evaluate their predictive value on the DA treatment.