C9orf72 and amyotrophic lateral sclerosis: Several genes encoding proteins with diverse cellular functions have been implicated as causative for ALS including C9ORF72, SOD1, TARDBP, FUS and VCP. Both astrocytes and microglia have been implicated as important modulators of the pathological process of motor neuron death in ALS in animal models of the disease (Boillée et al., 2006; Yamanaka et al., 2008).