LTF and Alzheimer disease: Part of the innate immune role of Lf during a pathogen invasion is to deplete extracellular iron essential for pathogen replication [35] and therefore the burden of brain iron that drives the onset of sporadic AD [67–69] may particularly receive contributions from activated microglia [70–72], and is likely also to increase the proportion of iron-loaded holo-Lf within the interstitial space.