We have focused our research on the subgroup MDS with ring sideroblasts (MDS-RS), characterized by ineffective terminal erythroid differentiation, recurrent somatic mutations in splicing factor 3b subunit 1 (SF3B1) [7–9] and accumulation of aberrant mitochondrial ferritin in erythroblasts, resulting in the generation of ring sideroblasts (RS) constituting 15–50% of nucleated erythroid bone marrow (BM) cells [10–14]. Here, SF3B1 is linked to myelodysplastic syndrome.