Venn diagrams illustrating the frequency of marker co-occurrence for AD and PiD, the two tauopathies with the highest marker positivity. Each coloured ellipse represents mean numbers of positive neurons for each antibody, including phosphorylated tau Ser396/404, mAbPHF-1 (green), mAbD402 (cyan) and mAbD13 (orange) identified by multiplex immunofluorescence. Abbreviations: AD, Alzheimers disease; PiD, picks disease; aCasp-6; active caspase-6; p-tau, phosphorylated tau