MAPT and Alzheimer disease: In Alzheimer’s disease, the reasons why iron can become unavailable can be multifold, including iron-binding protein aggregates such as amyloid β or tau, iron not undergoing proper transport from the lysosome to the cytosol, impaired recycling of iron-rich structures (ferritinophagy and mitophagy), and altered catabolism or production of heme, iron-containing proteins, or proteins linked with iron-related processes [1] (Figure 1).