SNCA and Parkinson disease: Recent evidence has illustrated that the detection of α-synuclein aggregates in the enteric nervous system can serve as a potentially useful and novel diagnostic target for neurodegenerative diseases,[22,23] and that α-synuclein aggregates also exist in the gastric nervous system of PD patients.[24] The latest evidence also suggests that the pathology of PD may occur from the gastrointestinal tract to the brain, as demonstrated in a mouse model.[18] Therefore, the detection of α-synuclein aggregates in the stomach and intestine may serve as a peripheral biological marker for PD diagnosis.