C9ORF72 mutant animal models, with one exception (Koppers et al., 2015), reported to recapitulate key molecular signatures unique to the intronic G4C2 repeat expansion, including RNA-foci and inclusions of dipeptide repeat (DPR) expansion inclusions, TDP-43 pathology, and behavioral abnormalities similar to symptoms observed in C9ORF72/ALS patients (Chew et al., 2015). This evidence concerns the gene TARDBP and amyotrophic lateral sclerosis.