Nr0b1 is an orphan nuclear receptor and a component of a cascade required for the development of the hypothalamic-pituitary-adrenal-gonadal axis. Nr0b1 acts as a coregulatory protein that inhibits the transcriptional activity of other nuclear receptors through heterodimeric interactions. Nr0b1 may also have a role in the development of the embryo and in the maintenance of embryonic stem cell pluripotency.