The correlations between hepcidin, and iron (r = 0.228, P = 0.13) (Fig. 3A), hepcidin and TIBC (r = 0.133, P = 0.39) (Fig. 3B), and hepcidin and ferritin (r = 0.18, P = 0.23) (Fig. 3C) were not statistically significant in AD patients, whereas in control subjects, those between hepcidin and iron (r = 0.57, P = 0.01), hepcidin and TIBC (r = 0.56, P = 0.01), and hepcidin and ferritin (r = 0.41, P = 0.05) all remained significant. Here, HAMP is linked to Alzheimer disease.