Figure 2. Model illustrating the regulation of a target gene by both retinoic acid receptor-related orphan receptors and REV-ERB.
REV-ERB functions as a receptor for heme, which is required for its activity as a repressor. Several sterols have been suggested as ligands for the RORs. In this cartoon, sterols regulate the constitutive activity of the RORs.
ROR: Retinoic acid receptor-related orphan receptor; RORE: ROR response element.