When I was a medical student, then a junior doctor, two papers struck me as being important even though I did not fully understand why. One was from a pioneer in prion diseases, Carlton Gajdusek, that hypothesised that all neurodegenerative disorders may have some common pathogenic basis [1]. The second paper by Tom Powell and Carl Pearson (who both taught me as an undergraduate) proposed that the pathology of Alzheimer’s disease followed a pattern of linked pathways that suggested spread of disease from the nose through the transfer of some pathogenic species of protein synaptically [2]. Fast forward to 2008 and we have the paper that is the subject of this Viewpoint which suggests protein spread as a common mechanism for many neurodegenerative disorders of the brain.