While MAPT methylation can be both increased and decreased, the genes/loci responsible for the expression of α-synuclein and PGC1-α (key factor in mitochondrial biogenesis) are hypo- and hypermethylated, respectively (for review see Zhang et al. [161]), indicating a crucial role for α-synuclein but also mitochondria in DLB/PD. This evidence concerns the gene SNCA and Lewy body dementia.