SNCA and Parkinson disease: The deposition of misfolded and aggregated alpha-synuclein (αSyn) in cerebral neuronal cell bodies or processes (referred to as Lewy bodies [LB] or Lewy neurites [LN], respectively [1]) and associated with synapses [2] is a neuropathological hallmark of idiopathic Parkinson’s disease (abbreviated in the following simply as PD, since other forms of Parkinson’s disease will not be addressed in this review).