Moreover, though some controversies exist, recent studies have indicated that liver X receptor (LXR) agonists or retinoid X receptor (RXR) agonists enhance apoE lipidation and secretion through the modulation of the ATB-binding cassette protein A1 (ABCA1), and benefit Aβ metabolism, neuropathology, and cognitive function in animal models of AD [8,9,10,11]. This evidence concerns the gene ABCA1 and Alzheimer disease.