The use of ratios normalised to Aβ levels instead of absolute aggregate quantities helped us to achieve greater biomarker performance and a larger dynamic range between patients and controls (from 1.5 to 1.7 fold increased single ASC speck biomarker to 3-5 fold increased (α-syn + ASC)/Aβ ratio in PD serum compared to controls and from 1.5-fold increased single ASC speck biomarker to 6.2-fold increased (p-tau-AT8 + ASC)/Aβ ratio in early AD serum compared to controls). This evidence concerns the gene MAPT and Parkinson disease.