MAPT and Alzheimer disease: We hypothesized that the possible loss of pH gradient in AD brain lysosomes, along with the presence of acetylated tau protein at the lysosomal membrane (Fig. 5c and Supplemental Fig. 5f, confirms a 50% reduction in the amount of acetylated tau that reaches the lysosomal lumen), could result in similar interruption of lysosomal translocation of tau proteins and persistence of L2A into multimeric complexes to the one observed in the in vitro system (Fig. 3d).