Figure 3: Induction of the human SULT2A1 promoter by PXR, CAR and a synergizing effect of HNF4-α. Schema showing a PXR- and CAR-binding composite XRE comprised of IR2 and DR4 elements, and an HNF4-α-binding DR1 element located downstream of XRE. Dotted, upward arrows signify promoter induction. Interaction between DR1-bound HNF4-α and XRE-bound PXR/RXR, CAR/RXR has an synergistic effect (triple upward arrows) on SULT2A1 induction. (based on results described in [9]).