SNCA and Parkinson disease: In PD, disease-associated α-synuclein is largely phosphorylated at position Ser129 (pSer129) (Fujiwara et al., 2002), and, in cultured cells expressing mutant A53T α-synuclein, both the stimulation of reactive oxygen species production and alterations to mitochondrial respiration highly correlate with levels of pSer129 (Perfeito et al., 2014).