As summarized in Table 5, those who harbored ID4 gene hypermethylation according to WHO subtypes included four (9.76%) of the 41 patients with RA, four (18.18%) of the 22 patients with refractory cytopenia with multilineage dysplasia (RCMD), one (14.29%) of the 7 patients with refractory anemia with ringed sideroblasts (RARS), eleven (52.38%) of the 21 patients with refractory anemia with excess blasts (RAEB)-1, and seven (77.78%) of the 9 patients with RAEB-2. The gene discussed is ID4; the disease is myelodysplastic syndrome with single lineage dysplasia.