Vitamin A and its derivatives, retinoids, have profound effects in development, differentiation, homeostasis and various aspects of metabolism. The discovery of retinoid receptors (Nuclear Class 2, Retinoid X Receptor-like) substantially contributed to understanding how these small, lipophilic molecules, most importantly retinoic acid (RA), exert their pleiotropic effects. After the identification of the all-trans retinoic acid receptor (ATRA), another receptor termed retinoid X receptor (RXR) was discovered, that was capable of mediating retinoid signaling pathways. Most importantly, RXR was shown to form heterodimers with many other nuclear receptors, making it unique among the members of the nuclear receptor family. The two families of retinoid receptors (RARs and RXRs) now consist of three isotypes, α, β, and γ, encoded by separate genes and giving rise to numerous alternatively spliced variants[1]. Bexarotene (Axon 1700) is an oral antineoplastic RXR antagonist developed for the treatment of cutaneous T cell lymphoma originally. Recently, it has been reported that bexarotene is also capable of reducing amyloid plaque and improving mental functioning in a small sample of mice engineered to exhibit Alzheimer's-like symptoms. It is hypothesized that this is mediated by Bexarotene-stimulated expression of apolipoprotein E (ApoE), which leads to intracellular clearance of β-amyloid[2].  

Retinoic acid receptors listed: RAR, RXR