Hypomethylation of the α-synuclein gene (SNCA) promoter region has been reported in the substantia nigra of PD patients in some studies (Jowaed et al., 2010; Matsumoto et al., 2010), yet it is not replicated in others (Richter et al., 2012; Guhathakurta et al., 2017). The gene discussed is SNCA; the disease is Parkinson disease.