TARDBP and Alzheimer disease: A study showed that the combination of extracellular vesicle-derived TDP-43 levels with 3-repeat or 4-repeat tau ratios had the ability to distinguish patients with ALS from those with frontotemporal dementia, as well as from healthy controls and people with other neurodegenerative diseases, such as Alzheimer’s disease.92 Other peripheral biomarkers in development include the detection of TDP-43 in platelets isolated from peripheral blood samples, which have disease-specific TDP-43 aggregation profiles and can carry neuronal and astrocyte-derived mRNA signatures.