The Retinoid X Receptor (RXR) is a type of nuclear receptor that plays a crucial role in regulating gene expression. It is activated by binding to retinoids, which are derivatives of vitamin A. RXR can form heterodimers with other nuclear receptors, such as the Thyroid Hormone Receptor and Retinoic Acid Receptor, enhancing their ability to regulate target genes involved in various biological processes. RXR is important for numerous physiological functions, including cell differentiation, development, and metabolism. It is found in many tissues throughout the body and is involved in processes like vision and immune response. Dysregulation of RXR activity can lead to various health issues, including certain cancers.