Specifically, the increased abundance of 3 proteins was significantly associated with an increased risk of PD, namely ENTPD1 (OR:26.240, 95%CI:8.246–83.500, P = 3.16E-08), GPNMB (OR:2.368, 95%CI:1.167–3.305, P = 3.95E-07) and FCGR2B (OR:1.346, 95%CI:1.163–1.557, P = 6.63E-05), while the increased abundance of 3 proteins was significantly associated with a decreased risk of PD, namely CTSB (OR:0.191, 95%CI:0.089–0.410, P = 2.19E-05) and CD84 (OR:0.053,95%CI:0.014–0.207, P = 2.23E-05). The gene discussed is CTSB; the disease is Parkinson disease.