APOE and tauopathy: Whereas possible key genes (MAPT, APOE, APP, SNCA) and risk loci of APs have been identified [1,212,213,214], and recent research has unveiled essential basic mechanisms of neurodegeneration in MSA [215] and tauopathies [216,217], our knowledge about the pathogenesis of CI in this range of disorders is mainly dependent on recent neuroimaging findings, while concerning CI in APs, respective neuropathological data are rather poor.