PRKN and Parkinson disease: The results demonstrated that the relationship between Parkin and PD was partially mediated by CEA and albumin with the approximate proportion of mediation of 22.68% (p = 0.04) and 25.83% (p = 0.02), respectively, rather than Hcy (proportion: 7.62%, p = 0.36), total proteins (proportion: 6.55%, p = 0.06), Urea (proportion: 12.58%, p = 0.10), and TC (proportion: −23.47%, p = 0.18).