C9 and amyotrophic lateral sclerosis: Transcriptome and histologic analyses of postmortem tissue from patients with ALS carrying the C9orf72 expansion (C9-ALS) found that decreased C9orf72 expression in C9-ALS led to altered microglial function and increased microglial activation.309,361 In Lall et al.’s study, Cd11b+ isolated microglia from young (3 months) and aged (17 months) C9orf72+/+, C9orf72+/-, and C9orf72-/- mice were analyzed by RNA-seq.