In autopsy studies, APOE4 was associated with dementia and diffuse LB pathology in ‘pure’ dementia with Lewy bodies patients (i.e. with absent or low levels of amyloid) as well as Parkinson’s disease dementia.24,25 Mouse models of synucleinopathy have also demonstrated that APOE4 exacerbated alpha-synuclein pathology in the absence of amyloid.26,27. The gene discussed is APOE; the disease is dementia.