CYCS and Alzheimer disease: Mitochondrial swelling occurs along with several mitochondrial perturbations, including multiple cellular stresses as ROS generation, calcium deregulation, mitochondrial membrane potential collapse, and the release of pro-apoptotic factors into the cytoplasm, such as cytochrome c. These mitochondrial perturbations, known as the “mitochondrial cascade hypothesis in AD”, precede the synaptic damage, the neuronal cell death, and the deficits in learning/memory ability in AD [6,14].