Another marker of iron metabolism is serum hepcidin, whose levels are significantly reduced in IDA (since iron absorption should not be inhibited in this context), elevated in chronic disease anemia and in obesity (in response to inflammatory stimuli, mediated by interleukin-6, hepcidin is released by hepatocytes), and inadequately normal or high in genetically determined iron deficiency anemia (IRIDA). The gene discussed is HAMP; the disease is IRIDA syndrome.