For example, ApoE4 is a ligand for the lipoprotein receptor-related protein (LRP), and ApoE4 polymorphisms are associated with poor prognoses in numerous neurodegenerative diseases, including Alzheimer's disease, stroke, hemorrhage, trauma, as well as HIV dementia/neuropathology. The gene discussed is LRP1; the disease is early-onset autosomal dominant Alzheimer disease.