A 2024 multicenter study analyzed extracellular vesicles (EVs), specifically neuronally derived serum EVs (NDEVs) (L1CAM-positive EVs) containing αSyn, and found that this biomarker distinguished individuals with isolated rapid eye movement sleep behavior disorder (iRBD)—a prodromal phase of PD—from controls with an area under curve (AUC) of 0.91. The gene discussed is L1CAM; the disease is Parkinson disease.