RAR beta
The RARB gene produces retinoic acid receptor beta, most prominently through its beta2 isoform, whose expression is itself induced by retinoic acid, forming a feed-forward loop in differentiation signaling. RAR beta heterodimerizes with RXR and regulates genes involved in growth arrest, apoptosis and tissue morphogenesis, with high expression in brain, lung and reproductive tissues. Its tumor-suppressive character is well documented: RARB promoter hypermethylation silences the receptor in breast, lung, cervical and head-and-neck cancers, and loss of RAR beta2 correlates with poor prognosis. Retinoid chemoprevention strategies partly rely on restoring RAR beta expression, and recombinant RAR beta serves in binding assays that distinguish beta-selective retinoids for dermatological and oncological applications.
