For example, most cases of sporadic FTD are due to either TDP-43 or tau pathology, and so the availability of a tau PET tracer able to detect 4R or 3R tau deposits would be an enabling technology for trials targeting either pathology—patients could be screened in or out based on a tau PET scan, depending on the target. The gene discussed is TARDBP; the disease is frontotemporal dementia.