Mechanistically, anemia of inflammation is mainly caused by inflammation-driven retention of iron in macrophages making the metal unavailable for heme synthesis in the course of erythropoiesis and further by impaired biological activity of the blood cell hormone erythropoietin and the reduced proliferative capacity of erythroid progenitor cells, i.e. anemia of inflammation is caused by iron trapping with the body mediated by the hepatic hormone hepcidin, the release of which is stimulated by infection-related production of the pro-inflammatory cytokine interleukine 6 [90]. This evidence concerns the gene EPO and anemia.