After adjusting for gender, there was a significant association between CD31 and UPDRS-III score, and Bonferroni adjustment for multiple comparisons revealed a significant difference between controls and PD patients with UPDRS-III score ≥31 and PD patients with a UPDRS-III score of 1–20, compared to those with a UPDRS-III score ≥31 (Fig. 2d). This evidence concerns the gene PECAM1 and Parkinson disease.