Univariate MR analysis results indicated a correlation between higher levels of Cathepsin B (IVW (OR): 0.89, 95% (CI): 0.83, 0.95, p = 0.001) and Cathepsin D (OR: 0.80, 95%CI: 0.68, 0.95, p = 0.012) with a decreased risk of Parkinson’s disease. The gene discussed is CTSB; the disease is Parkinson disease.