However, it was also reported that hepcidin mRNA and protein increased in the brain with aging (Wang et al., 2010); it can be up-regulated by inflammation (Urrutia et al., 2013), especially by interleukin-6, with the result of FPN1 decrease and iron retention in AD brains (Chaudhary et al., 2021), exerting the detrimental impact on the brain. This evidence concerns the gene SLC40A1 and Alzheimer disease.