MAPT and Parkinson disease: For insoluble 1N4R tau protein, a significant increase in H1/H1 PD brains was also found with significant effect of both MAPT haplotype (H1/H1 vs. H2/H2 3.2 ± 0.9 vs. 1.9 ± 0.5, F (1,22) = 4.54, P = 0.045) and disease (PD vs. Control 3.2 ± 0.8 vs. 1.8 ± 0.4, F (1.22) = 5.12, P = 0.034).