For over a century, neurodegenerative diseases like Alzheimer’s and Parkinson’s disease have been considered protein disorders, characterised by the accumulation of amyloid-beta plaques, tau tangles, and Lewy bodies. Research and drug development followed the same logic: target the proteins, slow the disease. The results, after decades of trials and considerable investment, have been largely disappointing. A growing body of research now suggests this framing may be incomplete....