Compared to C9– ALS patients (i.e., without the C9orf72 mutation), C9+ ALS patients had greater atrophy of extra-motor cortical regions, particularly parieto-occipital cortical areas, including the cuneus and precuneus (11–13), and relatively less atrophy of the precentral motor cortex (13, 14). Here, C9 is linked to amyotrophic lateral sclerosis.