Probable orphan nuclear receptor. Binds to a response element containing repeats of the motif 5'-AGGTCA-3'. Required for anterior-posterior patterning during organogenesis. Acts with chordin to play a role in patterning the midbrain-hindbrain. Isoform Em is required for integrin-mediated cell matrix interaction during neurulation and for the morphogenetic movements leading to formation of the neural tube. Also mediates the effect of retinoic acid on primary neurogenesis (By similarity). Homodimer. Belongs to the nuclear hormone receptor family. NR6 subfamily.