GFAP and Splenomegaly: The number or GFAP positive cells and Iba-1 positive cells were similar to controls (Supplementary Figures 1C–F) and there was no sign of peripheral inflammation like splenomegaly (Supplementary Figure 1G), previously observed in C9orf72 knockout animals (Atanasio et al., 2016; Burberry et al., 2016; Jiang et al., 2016; O’Rourke et al., 2016).