RXRB (retinoid X receptor beta) is a nuclear receptor that functions as a transcription factor regulating gene expression through retinoic acid signaling pathways 1. The gene produces two major isoforms (RXRβ1 and RXRβ2) generated by alternative splicing from separate CpG island promoters, with RXRβ1 containing an additional 72 amino acid N-terminal domain 1. RXRB forms heterodimers with other nuclear receptors and binds to retinoic acid response elements to regulate transcription. In reproductive biology, RXRB is primarily expressed in Sertoli cells and its reduced expression is associated with severe spermatogenic failure including Sertoli cell-only syndrome and maturational arrest 2. The receptor plays roles in cancer biology, where it functions downstream of RAB39A to maintain cancer stemness and spherogenic ability 3. Additionally, RXRB serves as a transcription factor regulating B cell proliferation in acute lymphoblastic leukemia 4. Genetic variants in RXRB are associated with autoimmune diseases, particularly anti-topoisomerase I antibody-positive systemic sclerosis 5. The gene also contributes to cardiovascular health, with upregulated RXRB expression observed following Mediterranean dietary interventions in high-risk patients 6 and shows associations with adult lung function 7.