Among the three specific DPP4 inhibitors analyzed (sitagliptin, vildagliptin, and linagliptin), vildagliptin was associated with a 64% reduction in PD incidence (aHR, 0.46; 95% CI 0.27–0.77), while the other two drugs did not show strong evidence of a lower PD risk (aHR, 0.96; 95% CI 0.69–1.32 and aHR, 0.56; 95% CI 0.31–1.03, respectively). This evidence concerns the gene DPP4 and Parkinson disease.