In this review, we discuss the growing body of findings and the emerging concepts about DMT1 and NTBI involvement in both physiological aging and neurodegeneration/neuroinflammation, as found in Parkinson’s disease (PD), ischemia, Neurodegeneration with Brain Iron Accumulation (NBIA), and Alzheimer’s disease (AD). The gene discussed is SLC11A2; the disease is Alzheimer disease.