Proteins associated with neurodegenerative disorders such as the prion protein in transmission spongiform encephalopathies, Amyloid Precursor Protein (APP) in Alzheimer’s disease, and mutations of cytosolic CuZn superoxide dismutase (SOD1) involved in the familial amyotrophic lateral sclerosis (ALS) can be incorporated into ILVs and released into the exosome-enriched extracellular environment [10]–[14]. Here, APP is linked to familial amyotrophic lateral sclerosis.