Other proteins (SDCBP2, ENTPD1, ITGB2, and C1QTNF1) that our MR analyses suggest are causal were genetically associated with PD risk based on the PWAS analyses and some (ENTPD1, ITGB2, and C1QTNF1) showed significant differential protein levels in PD cases compared to controls on the PPMI dataset. Here, ITGB2 is linked to Parkinson disease.