We have reproduced a PDX model by xenografting HSC (CD34+) and mesenchymal stromal cells (MSC) in NOD/SCID/IL2rγ-/- mice with primary samples from one RAEB2, two RAEB1 and one RARS patients harboring karyotype abnormalities and gene mutations. This evidence concerns the gene IL2RG and myelodysplastic syndrome with ring sideroblasts.