According to National Comprehensive Cancer Network (NCCN) guidelines, epigenetic mutations such as TET2, DNMT3A, ASXL1, IDH1/2, and EZH2 commonly occur in MDS; Splicing factor-related mutations such as SF3B1, SRSF2, U2AF1 and ZRSR2 are not specific mutations of MDS but occur more frequently in MDS than in other myeloid tumors. The gene discussed is ASXL1; the disease is myelodysplastic syndrome.