C9orf72 and amyotrophic lateral sclerosis: This protein is of great interest in the study of neurodegenerative diseases, especially for ALS-FTD, because, independently of the familial or sporadic occurrence, it forms cytoplasmic neuronal inclusions in more than 95% of the cases; of note, TDP-43 aggregates have been documented even in the absence of specific genetic mutations, or in C9orf72 ALS-FTD cases [56].