FGF20 and Parkinson disease: Pathological analysis reveals positive correlation between expression level of FGF20 and α-Synuclein, whereas overexpression of α-Synuclein is previously reported to cause PD, which implies pathogenesis of the T-allele is to abolish the interaction between FGF20 gene and miR-433 thus lead to up-regulation of α-Synuclein.