Therefore, to gain insight into the clonal landscape of coexisting mutations in SF3B1 mutant MDS-RS patients, we performed a single-cell clonogenic assay using CD34+ cells from four patients (MDS1, time point 1; MDS2, TP1; MDS3; MDS4), followed by targeted mutational analysis of the patient-specific mutations. The gene discussed is CD34; the disease is myelodysplastic syndrome.