FIGURE 2: An overview of the autophagy pathway and the site of action of disease-associated proteins. A huge number of neurodegenerative disease-related genes have been implicated in autophagy function. Mutation or deletion of these genes have been suggested to be involved in perturbation throughout the autophagic process, from initiation of autophagosome formation to degradation in the autolysosomes. Their proposed sites of action are highlighted in boxes. Please note that some disease-associated proteins act at multiple points in the process. AD – Alzheimer disease; PD – Parkinson's disease; HD – Huntington's disease; ALS – amyotrophic lateral sclerosis.