C9orf72 and amyotrophic lateral sclerosis: Using the single center Emory CSF cohort, we compared CSF proteomes from sALS (n = 35), C9orf72 ALS (n = 10), C9orf72 asymptomatic carriers (n = 6), SOD1 ALS (n = 6), and healthy controls (n = 44) with the goals of discovering differences between ALS and control, and protein signatures that may differentiate the ALS subtypes (Fig. 1a).