Quantitative analyses revealed a significant reduction in the expression of SNPH in Braak IV-VI AD brains versus age-matched non-demented control brains (Fig. 9A, B), while TRAK2 (Fig. 9A, E) and IC1,2 (Fig. 9A, H) levels were gradually reduced in a disease-dependent manner (i.e., Braak IV–VI AD brains versus Braak stages (I–III) AD brains). This evidence concerns the gene TRAK2 and Alzheimer disease.