Enhances the transcriptional activities of several nuclear receptors. Involved in the coactivation of different nuclear receptors, such as ESR1, THRB, PPARG and RARA. Interacts with ESR1, ESR2A, ESR2B, THRB, PPARG and RARA in a ligand-inducible manner. Interacts with the heterodimer AHR-ARNT. Highly expressed in brain. Weakly expressed in mammary gland, ovary, uterus, prostate, stomach, bladder, spinal cord and pancreas. Expressed in cancer cell line. Belongs to the OXR1 family.