Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) belong to a spectrum of neurodegenerative diseases with overlapping symptoms, characterized by muscle wasting, paralysis, dementia, and other serious impairments. There are currently no effective treatments. Many patients have a common hallmark: A protein called TDP-43 clumps together in the neurons of the brain to form tiny lumps. Researchers at DZNE and Ulm University Hospital, together with international experts, have now discovered that these pathological changes primarily affect certain cells.