The NGFI-B subfamily of the nuclear receptor superfamily (review).

NGFI-B, Nurr1 and NOR-1 have structural features of ligand-activated transcriptional regulators and constitute the NGFI-B subfamily within the nuclear receptor superfamily. Since specific ligands for these molecules have not yet been identified, they are often called orphan nuclear receptors. Genes of the NGFI-B subfamily are classified as immediate-early genes that are induced rapidly but transiently by a variety of stimuli. Evidence accumulated over the past decade suggests this subfamily is involved in important physiological processes and cancer development. In this communication, we summarize and discuss their structural features, gene expression, physiological roles and oncological significance.