C9orf72 and amyotrophic lateral sclerosis: However, a common finding from murine C9orf72 knockout models is the lack of neurodegeneration or TDP-43 pathology—a key pathological feature of C9orf72-ALS/FTD (O’Rourke et al., 2015; Atanasio et al., 2016; Burberry et al., 2016; Jiang et al., 2016; Sudria-Lopez et al., 2016; Sullivan et al., 2016).