CSF levels of Aβ42 were lower in DLB patients carrying two APOE ε4 alleles than in non-carriers (p < 0.05, Fig. 4a), and the Aβ42/Aβ40 and Aβ42/Aβ38 ratios were lower in APOE ε4 carriers compared to non-carriers in a gene dose-dependent manner (p < 0.05, Fig. 4d, e). Here, APOE is linked to Lewy body dementia.