Researchers have found, for the first time, that a blood-clotting protein can, unexpectedly, degrade nerves–and how nerve-supporting glial cells, including Schwann cells, provide protection. The findings show that Schwann cells protect nerves by blocking this blood-clotting protein as well as other potentially destructive enzymes released by muscle cells. The work could have implications for diseases as diverse as amyotrophic lateral sclerosis (ALS), multiple sclerosis, Alzheimer’s disease or schizophrenia.