MAPT and Alzheimer disease: The co-expression of tau, Aβ and α-syn has been reported in the limbic and cortical regions, particularly in the hippocampus and neocortex in human postmortem studies from DLB, AD and PDD brains (Colom-Cadena et al., 2013, Ferman et al., 2018, Kouli et al., 2020).