SNCA and Parkinson disease: The cellular hallmarks of PD include the loss of dopamine neurons in the substantia nigra, the formation of LB in α-synuclein aggregation.[17] After establishing a theory based on the local anatomical distribution of LB through the autopsy of the brain in patients with PD, Braak et al[12] assumed that the early formation of LBs occurred in the gastrointestinal tract, gradually spreading to the brain, which suggested the presence of jumping retrograde axoplasmic transport of α-synuclein through vagus.