HX-531 is a potent antagonist of the retinoid X receptor (RXR) with an IC50 value of 18 nM. HX531 has been used in many studies of the various effects of retinoids and RXR activity in diseases such as diabetes, Parkinson′s disease, often as a control for agonists such as Bexarotene. It was recently shown to promote white adipogenic differentiation and inhibit both basal and Bexarotene-induced brown adipogenic differentiation.