One of the most common genetic causes for both ALS and frontotemporal dementia (FTD), a closely related neurodegenerative condition that shares both genetic and pathological signs with ALS, is a GGGGCC hexanucleotide repeat expansion (HRE) in the C9ORF72 gene (C9-ALS) [2]. The gene discussed is C9; the disease is frontotemporal dementia.