Ferritinisimportantinironhomeostasis.Itisthemainiron-storageprotein,composedoftwopartiallyhomologoussubunits,heavyandlightchains.Ferritinmoleculesincellscontaininghighlevelsofirontendtoberichinlightchains,andmayhavealong-termstoragefunction,whereasheavy-richferritinsaremoreactiveinironmetabolism.Mutationsintheferritingenecausethehereditaryhyperferritinemia-cataractsyndromeandneuroferritinopathy,associatedwithinflammation.Elevatedlevelsofferritinarereportedascharacteristicofadult-onsetStill'sdiseaseandhemophagocyticsyndrome,alsoassociatedwithinflammation.MICROFILamentsandincreasedlevelsofexogenousferritinareexcreteddirectlyintothebilebywayofasecondmicrofilament-independent,chloroquine-insensitivepathway,supportingapossIBLephysiologicalmechanismforthereleaseofferritinfromtheliver.