Furthermore, systemic inflammation and high levels of TNF-α can bias hematopoiesis toward myeloid-cell production, inhibit erythroid-precursor proliferation, shorten the erythrocyte lifespan, and inhibit the release of recycled iron from macrophages (mediated by IL-6), causing hypoferremia and anemia, which may increase complications and mortality in surgical and critically ill patients [34]. This evidence concerns the gene TNF and anemia.