APOE alleles differ in CpG content and in ε3/ε4 genotype carriers, APOE CpG island methylation was significantly decreased in the frontal lobe of AD and DLB patients, with the most significant decrease in DLB patients with mixed AD and LB pathology, as compared to pure AD or LB pathology cases [73]. The gene discussed is APOE; the disease is Alzheimer disease.