SNCA and Parkinson disease: The connection between PD and mitochondria is reinforced by heritable forms of the disease, wherein monogenetic PD-causing mutations in nuclear-expressed proteins such as PINK1, Parkin, LRRK2, and alpha-synuclein have all been shown to affect mitochondrial function (Narendra et al., 2010; Sanders et al., 2014; Di Maio et al., 2016; Verma et al., 2017).