Similar to the immunohistochemical findings, quantitative analysis of RIPA-buffer extracted vessel enriched brain lysates demonstrated a significant decrease in total PDGFR-β levels in AD patients in comparison to non-demented controls (Fig. 3b) and a positive correlation between total PDGFR-β and Aβ34 levels in non-demented individuals (Fig. 3c). This evidence concerns the gene PDGFRB and Alzheimer disease.