Although these proposed pathomechanisms are not mutually exclusive, these DPRs, namely glycine–alanine (GA), glycine–arginine (GR), glycine–proline (GP), proline–alanine (PA), and proline–arginine (PR) have been, respectively, identified in ALS or FTD patients with C9orf72 repeat expansions and thus drawn enormous attention18,19. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.