Regarding SV2A density (Fig. 4B), a significant negative correlation with NfL immunoreactivity was found in the regions affected at Braak 4 of PD cases (r = -0.35, R2 = 12%, p = 0.030), and at Braak 6 of DLB cases (r = -0.83, R2 = 69%, p < 0.001). Here, NEFL is linked to Parkinson disease.