Somatic mutations at the RNA splicing factor 3b subunit 1 (SF3B1) coding gene are recurrent in patients with MDS with ring sideroblasts (MDS-RSs), like in refractory anemia (RARS) and refractory cytopenia with multilineage dysplasia (RCMD-RS) [46]. The gene discussed is SF3B1; the disease is myelodysplastic syndrome.