A small new trial published in the journal Nature Medicine describes what would be two firsts for Parkinson’s disease, if they pan out: a diagnostic test and a potential immune-based treatment that works similarly to a vaccine. The research is still early, but researchers are excited by the prospect of advances for a disease that lacks good diagnostics and treatments. The target of both innovations is alpha synuclein, a protein that takes an abnormal form in Parkinson’s patients—aggregating in their brains and destroying nerve cells involved in motor and some cognitive functions.