C9orf72 and amyotrophic lateral sclerosis: We previously described the development and characterization of a mouse model of c9FTD/ALS whereby the expression of (G4C2)66 throughout the central nervous system (CNS) by means of somatic brain transgenesis using an adeno-associated virus (AAV) vectors resulted in the development of C9orf72-associated pathological and behavioral abnormalities by 6 months of age [9].