RNA expression analyses have indicated that pathways including the complement system, antigen presentation, and interferon (IFN) γ and interleukin (IL) 1-β signaling are significantly upregulated in the brains of C9-ALS patients compared to sporadic ALS patients (Prudencio et al., 2015; O'Rourke et al., 2016). Here, C9 is linked to amyotrophic lateral sclerosis.