Currently, there are few predictive markers for response that can guide treatment decisions for patients with lower-risk MDS, such as low endogenous EPO levels predicting response to ESAs or presence of del(5q) indicating lenalidomide treatment.17,85 Additional predictive molecular biomarkers would have great clinical utility and in recent years, much research has been focused on the identification of predictive gene mutations.86 However, currently there are no evident molecular biomarkers for response to ESAs. The gene discussed is EPO; the disease is myelodysplastic syndrome.