CSF3 and myelodysplastic syndrome: A treatment option for patients with lower-risk non-del(5q) MDS who have no response or stop responding to ESAs is a combination of lenalidomide and EPO with or without G-CSF.17,80 Interestingly, the response to lenalidomide in patients with lower-risk non-del(5q) MDS seems to be inversely correlated with the pre-treatment serum EPO levels.81,82 In particular, a randomized phase III study showed that patients with EPO ≤500 mU/mL had significantly higher response rates of RBC-TI ≥8 weeks vs patients with EPO >500 mU/mL (34.0% vs 15.5%; p = 0.015).26