Biochemical analysis of insoluble protein extracts isolated from affected FTLD-U and ALS tissue revealed a characteristic biochemical profile of TDP-43 with detection of disease-specific bands at ~25kDa, ~45 kDa and a smear of high-molecular-mass proteins in addition to the normal 43 kDa band. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.