RAR-related orphan receptor B (RORB) is considered to have intrinsic transcriptional activity, binding some natural ligands such as all-trans retinoic acid (ATRA) and other retinoids which act as inverse agonists that repress transcriptional activity. It is required for normal postnatal development of rod and cone photoreceptor cells. RORB modulates rod photoreceptor differentiation by inducing the transcription factor NRL-mediated pathway. In cone photoreceptor cells, it regulates transcription of OPN1SW. It is involved in the regulation of the period length and stability of the circadian rhythm. RORB controls cytoarchitectural patterning of neocortical neurons during development, and it regulates barrel formation upon innervation of layer IV neurons by thalamocortical axons in a dose-dependent manner. References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804