MAPT and cerebral amyloid angiopathy: To determine the relationship of the p-tau262 and p-tau356 immunosignal with p-tau202/205 labeling in pre-NFTs that lack tau fibrils and in NFTs that contain fibrillar tau, we performed triple fluorescence labeling experiments combining p-tau262 or p-tau356 with p-tau202/205 and the pan-amyloid binding dye X-34, which labels tau fibrils in NFT and Aβ fibrils in plaques and cerebral amyloid angiopathy.