C9orf72 and amyotrophic lateral sclerosis: Finally, the ALS-associated hexanucleotide repeat expansion in C9ORF72, which is the most common genetic cause of ALS and FTD, provides several connections to SG biology: loss of normal C9ORF72 function impairs the interaction with p62 and normal autophagy [76], pathological dipeptide proteins that are generated in C9ORF72 disease incorporate into SGs, form cytotoxic aggregates and impair normal SG dynamics [48,105,106], in part by induction of ER stress [107,108] and in part by sequestering the proteasome [92,93].