Somatic mutations in the splicing factor SF3B1 occur in about one-third of all myelodysplastic neoplasms (MDS) and define a subgroup of patients characterized by ring sideroblasts (RS), ineffective erythropoiesis, and an indolent disease course in lower-risk (LR) MDS [1]. The gene discussed is SF3B1; the disease is myelodysplastic syndrome.