We observed that plasma α-synuclein levels showed high positive correlation with IL-1β of plasma in PD patients (Fig. 5b, r = 0.5885, p < 0.0001), while no correlation was found between the plasma levels of IL-1β and α-synuclein in healthy controls (Fig. 5a, r = − 0.1291, p = 0.5477). Here, IL1B is linked to Parkinson disease.