Mounting evidence has demonstrated that proteins implicated in neurodegenerative diseases, such as Alzheimer’s (amyloid-β, tau), Parkinson’s (α-synuclein) and ALS (SOD1 and TDP-43), feature pathological propagation of protein aggregation, which is thought to be due to the recruitment of soluble proteins into aggregates through a prion-like seeding mechanism36. Here, SOD1 is linked to neurodegenerative disease.