To evaluate if factors known to have an effect on erythropoiesis and to be altered in MDS-RS [36–38] were differentially secreted in NBM and MDS-RS cultures we measured the concentration of transforming growth factor (TGF)-β1, growth differentiation factor 11 (GDF11), interleukin 10 (IL-10) and interleukin 1 alpha (IL-1α) in medium collected from MNC and CD34+ 3D cultures at week 1, 2, and 4. Here, GDF11 is linked to myelodysplastic syndrome.