In iron-loading anemias, ineffective erythropoiesis suppresses hepcidin production, which result in dysregulating iron homeostasis. Miller and co-workers showed that release of cytokines like growth differentiation factor 15 (GDF15) during the process of ineffective erythropoiesis inhibits hepcidin production, thus defining a molecular link between ineffective erythropoiesis, suppression of hepcidin production and parenchymal iron loading.