Alpha‐synuclein (α‐synuclein or SNCA), a soluble presynaptic protein belonging to the synuclein protein family, is known to form insoluble fibril aggregates, which play a very important role in the pathogenesis of Parkinson's disease (PD), however, its precise role in carcinogenesis is not clearly understood. The gene discussed is SNCA; the disease is Parkinson disease.