IL16 and Parkinson disease: Examining PD and Ctrl groups only, we found that low levels of t-α-syn (OR, 0.996; 95% CI, 0.994–0.999), high levels of o-α-syn (OR, 1.031; 95% CI,1.005–1.056), high levels of pS129-α-syn (OR, 1.035; 95% CI, 1.010–1.059), low levels of IL-16 (OR, 0.785; 95% CI, 0.603–1.022) differentiates the PD group from the Ctrl group.