MAPT and amyotrophic lateral sclerosis: Similar differences in α-synuclein (ALS versus PD fc = -1.43, unadjusted p < 0.001) but not tau levels (ALS versus AD fc = -0.82, unadjusted p = 0.094) were observed in the detergent-insoluble fraction from spinal cord (Fig. 1C).