Accumulating evidence has revealed that brain iron concentrations increase with aging, and the choroid plexus may be at the basis of iron-mediated toxicity and the increase in inflammation and oxidative stress that occurs with aging.It includes not only hepcidin, the key hormone in iron metabolism, but also iron-related proteins and signaling-transduction molecules, such as IL-6 and signal transducer and activator of transcription 3, which becomes phosphorylated.