The importance of LXR-β in brain function is supported by previous studies showing that LXR-β deficiency is associated with central nervous system pathologies and brain development abnormalities as reported in recent studies in which the genetic ablation of LXRß in APP transgenic mice results in increased amyloid plaque load [7] demonstrating that LXRs ameliorate the pathogenesis of the neurodegenerative diseases, such as AD, PD, multiple sclerosis, and Huntington's disease. The gene discussed is NR1H2; the disease is Alzheimer disease.