C9orf72 and amyotrophic lateral sclerosis: The hexanucleotide repeat expansion in the non-coding region of C9ORF72 is the most common cause of ALS that regulates endosomal trafficking and is colocalized with Rab1, Rab5, Rab7 and Rab11, indicating the involvement of C9ORF72 in autophagosome formation [167].