The characteristic pathological features in both ALS-C9 and FTLD-C9 cases is region-specific neuronal loss, gliosis, as well as accumulation of expanded transcripts in nuclear RNA foci and cytoplasmic TDP-43 aggregates (DeJesus-Hernandez et al., 2011; Renton et al., 2011; Liu et al., 2019). The gene discussed is C9; the disease is amyotrophic lateral sclerosis.