The data were filtered by proteins present in at least 50% of samples in one of the six groups (sporadic ALS, C9orf72 ALS, sporadic FTD, C9orf72 FTD, asymptomatic C9orf72 HRE carrier, and asymptomatic non‐carrier), leaving 1,245 for analysis. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.