Transcription factor that, in osteoblasts, activates the decoy receptor for RANKL, TNFRSF11B, which in turn regulates osteoclast differentiation. Acts in synergy with the Wnt-responsive LEF1/CTNNB1 pathway. Recognizes variations of the palindromic sequence 5'-ATTCCCNNGGGAATT-3'. Forms either a homodimer or a heterodimer with a related family member (PubMed:9151732). Interacts with SIX1 (PubMed:27923061). In adult expressed in olfactory epithelium and at a much lower level in Purkinje cells of the cerebellum. In embryo expressed in epithalamus, in cells near the ventricular zone of mesencephalon and on the ventral surface of rhombencephalon, in the developing vomeronasal organ, at a lower level in developing spinal cord. Not expressed in developing retina, inner ear, dorsal root ganglia, trigeminal ganglia and glossopharyngeal ganglia. First detected at 9.0 dpc in the first and second archial arches. At 10.0 dpc and 10.5 dpc, expressed in somites, especially the forming sclerotomes. At 12.5 dpc, found in dorsal root ganglia. At 16.5 dpc, expressed in bone-forming areas and adipose tissues, as well as in specific neural tissues. In bone-forming areas, expressed along the mesenchymal condensation at 14.5 dpc, in the perichondrium and in cells invading the cartilagenous structures at 16.5 dpc. In 18.5 dpc tibias, scattered throughout the trabecular/cancellous bone area. In vitro, expression is induced during differentiation of immature osteoblasts, and then declines. Belongs to the COE family.