Based on the analysis of the targeted sequencing data of MDS, 17 candidate genes (DNMT3A, GATA1, GATA2, TP53, RUNX1, KRAS, NRAS, SRSF2, TET2, IDH1, IDH2, ETV6, EZH2, BCOR, PTPN11, STAG2, U2AF1) were identified. The gene discussed is PTPN11; the disease is myelodysplastic syndrome.