An international consortium published one of the world’s largest proteomic datasets linking blood protein signatures with major neurodegenerative diseases including Alzheimer’s, Parkinson’s, frontotemporal dementia, and ALS. The dataset comprises over 250 million protein measurements from 35,000 biofluids contributed by 23 groups. The findings identify shared and disease-specific diagnostic and therapeutic targets, enable early detection, and demonstrate the power of collaborative proteomics in untangling complex neurodegeneration biology.