The striking functional and structural similarities between FUS and TAR DNA-binding protein-43 (TDP-43), which are both DNA/RNA binding proteins whose mutations have been linked to the pathogenesis of both ALS and frontotemporal dementia (FDT), suggest that abnormal functioning/expression of these two related proteins can be pivotal event in ALS and FTD8. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.