When using PON1 (coded by PON1) as exposure and PD as outcome, the primary outcome of IVW model showed that the higher risk of PD was significantly associated with a decreased level of PON1, which indicated PON1 probably had protective effect on PD risk (OR[95%CI] = 0.81 [0.66, 0.99], p =0.04) (Figure 3C). This evidence concerns the gene PON1 and Parkinson disease.