MAPT and Parkinson disease: On the other hand, p-NfM/H positively correlated with p-tau load in the PDD/DLB group across all regions (r = 0.29, R2 = 8%, P = 0.043), which was a trend in PD (r = 0.32, P = 0.066), and absent in controls (P = 0.149) (Fig. 4b).