ARNT (aryl hydrocarbon receptor nuclear translocator) is a nuclear translocator protein that functions as an essential heterodimerization partner for the aryl hydrocarbon receptor (AHR). Upon AHR ligand binding, ARNT translocates to the nucleus where it forms a transcriptionally active AHR-ARNT complex 1. This heterodimer binds to xenobiotic response elements (XREs) and dioxin response elements (DREs) with core sequences 5'-TACGTG-3' and 5'-TGCGTG-3' respectively to regulate gene transcription 2. ARNT can also heterodimerize with HIF-1α to mediate hypoxic responses 3. The AHR-ARNT axis regulates diverse biological processes including drug metabolism, immune responses, and skin barrier function by upregulating genes like filaggrin and claudins 45. Beyond canonical signaling, ARNT participates in non-canonical pathways involving crosstalk with other transcription factors and signaling molecules 6. Clinically, ARNT dysfunction is associated with multiple malignancies, including glioblastoma where elevated ARNT correlates with poor prognosis and chemoresistance through p38-MAPK activation 7. AHR agonists activating ARNT, such as tapinarof and benvitimod, show therapeutic potential in inflammatory skin diseases like psoriasis and atopic dermatitis 45.