As displayed in Table 1 and Supplementary Figure 1, by using a significant threshold of 2.63 × 10–3 (Bonferroni correction for the correlation test of 19 cytokines), we found that genetically predicted one-SD increment in circulating MIP1b levels was associated with 6% higher risk of PD based on 74 SNPs in the IVW method (OR: 1.06; 95% CI: 1.02–1.10; P = 0.001). Here, CCL4 is linked to Parkinson disease.