We postulated that the low risk of MDS/AML is due to the loss of the EIF6 gene, mapping in the deleted segment of chromosome 20: the function of the EIF6 protein is pivotal in ribosome biogenesis, and the gene/dosage effect consequent to the gene loss would facilitate ribosome formation, impaired in SDS by SBDS mutations [5]. The gene discussed is EIF6; the disease is myelodysplastic syndrome.