SNCA and Parkinson disease: The search strategy combined MeSH terms and free-text keywords using Boolean operators, with the following terms: “exosomal microRNAs”, “Parkinson’s disease”, “dopaminergic neurodegeneration”, “biomarkers”, “oxidative stress”, “neuroinflammation”, “α-synuclein”, “mitochondrial dysfunction”, “extracellular vesicles”, “synaptic dysfunction”, and “gene regulation”.