Here, we provide evidence that PINK1/Parkin-mediated mitophagy is impaired in the hippocampus of AD patients, in induced pluripotent stem cell-derived human AD neurons, and in animal AD models, that impaired removal of defective mitochondria is a pivotal event in AD pathogenesis and that mitophagy represents a potential therapeutic intervention [32]. The gene discussed is PRKN; the disease is Alzheimer disease.