The hypothesis of α-synuclein prion-like propagation has gained attention in the recent years, since it has been shown that transplantation of healthy fetal mesencephalic neurons in PD patients led to the formation of LB-like inclusions, indicating the direct transfer of pathogenic α-synuclein from host brain to grafted neurons (Kordower et al., 2008; Li et al., 2008). This evidence concerns the gene SNCA and Parkinson disease.