To date, reduced expression of select or total C9orf72 transcripts [1, 6, 14, 20] or its protein level [57, 61] in C9orf72 G4C2 repeat carrier-derived cells or postmortem tissues from C9-ALS/FTD patients have been widely reported. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.