MAPT and Parkinson disease: The ratios of CSF-p-tau to CSF-Aβ42 were significantly increased in AD (0.125 ± 0.02) compared with Kii ALS/PDC (0.043 ± 0.02; P < 0.008), ALS (0.035 ± 0.019; P < 0.003), PD (0.025 ± 0.02; P < 0.002), and C (0.027 ± 0.09; P < 0.014) (Figure 1(d)).