C9orf72 and amyotrophic lateral sclerosis: To test whether the AAV9-engineered mouse model develops other pathological hallmarks of ALS/FTD such as C9orf72-derived RAN (c9RAN) protein aggregates, TDP-43 inclusions and neuronal loss, we used an anti-poly-GA antibody (Mackenzie et al., 2013) to probe for glycine-alanine-rich DPRs in mouse brains.