APP and Alzheimer disease: Devi et al. showed that Alzheimer’s amyloid precursor protein 695 (APP), a plasma membrane protein known to be the source of the toxic amyloid β (Aβ) peptide associated with the pathogenesis of Alzheimer’s disease (AD), formed a stable ~480 kDa complex with the TOMM40 import channel in mitochondria of human AD brains but not in age-matched controls, thereby inhibiting mitochondrial protein import, which led to defective mitochondrial functioning [100].