An emerging figure, while largely omitted from this review, is the multisystem nature of ALS and FTLD, where TDP-43 pathology in degenerating neurons has been linked to extracellular factors, including inflammation, microglial toxicity, and intercellular C9orf72-derived dipeptide transmission [43, 161–163]. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.