We studied the role of the levels of mRNA for transcriptions factors Fli-1 (Friend leukemia virus integration 1) and EKLF (erythroid Krűppel-like factor, also named KLF1) in mononuclear cells isolated from bone marrow and peripheral blood of MDS patients with 5q-syndrome in comparison with patients with low risk MDS without 5q chromosome abnormality and with healthy controls [124, 125]. This evidence concerns the gene KLF1 and myelodysplastic syndrome.