C9orf72 and amyotrophic lateral sclerosis: Interestingly, we detected β-gal puncta in a significantly greater percentage of CC1-positive oligodendrocytes in motor cortex than primary somatosensory cortex (Fig. 7a,b; p = 0.014, Chi-Square test), indicating enrichment of C9orf72 expression in cortical regions which undergo the most profound degeneration in ALS.