Taken together, these and other in vitro and in vivo studies suggest that altered mitophagy (for refs, see [108])—baseline mitophagy levels reduced by 30–50% in post mortem hippocampal brain samples of AD patients, compared to normal [109]—could be both an upstream and downstream step in the nefarious appearance of Aβ and Tau along a vicious circle that causes synaptic dysfunction and cognitive deficit [107]. This evidence concerns the gene MAPT and Alzheimer disease.