SNCA and Parkinson disease: Firstly, dysfunction of autophagy and UPS, the two main ways to clear toxic α-synuclein [65, 66], might lead to neuronal toxicities; secondly, both nitration and oxidation decrease the propensity of α-synuclein to form stable conformations, which might contribute to the progression of PD; in addition, truncated α-synuclein species have also been reported in Lewy bodies [20].