GPNMB and Parkinson disease: Epigenetic modifications of specific genes (i.e. synuclein alpha, SNCA; leucine rich repeat kinase 2, LRRK2; parkin RBR E3 ubiquitin protein ligase, PARK2; parkinson disease 16, PARK 16/Iq32; glycoprotein nmb, GPNMB and histone deacetylases, (HDAC) seem to be implicated in neurological disorders (e.g. epilepsy, schizophrenia, Alzheimer and Parkinson diseases) [95–98] and although most of the evidence in this field derive from animal models, numerous studies in the last few years have shown that the central nervous system plasticity is subjected to epigenetic regulations induced by exercise.