The association of ApoE4 polymorphisms with worse prognoses in numerous neurodegenerative diseases, such as AD, stroke, hemorrhage and HIV dementia, and neuropathy (Strittmatter et al., 1993; Roses et al., 1995; Slooter et al., 1997; Corder et al., 1998), suggest a key role of LRP and their ligands in association with dementia. The gene discussed is APOE; the disease is Alzheimer disease.