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). This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.