SLC18A2 and Parkinson disease: Nevertheless, despite an array of molecular hallmarks shared between aging and PD, including regression of dopamine synthesis [24,25], reduced cerebral density of the type 2 vesicular monoamine transporter (VMAT2) [26], elevated levels of deleted mitochondrial DNA [27], and inflammation [28], it is still of active debate whether PD represents as a form of accelerated aging [28].