Germ cell nuclear factor receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Nuclear Hormone Receptors [1]) have yet to be officially paired with an endogenous ligand.

* Key recommended reading is highlighted with an asterisk

* Benoit G, Cooney A, Giguere V, Ingraham H, Lazar M, Muscat G, Perlmann T, Renaud JP, Schwabe J, Sladek F, Tsai MJ, Laudet V. (2006) International Union of Pharmacology. LXVI. Orphan nuclear receptors. Pharmacol Rev, 58 (4): 798-836. [PMID:17132856]

* Garattini E, Bolis M, Gianni' M, Paroni G, Fratelli M, Terao M. (2016) Lipid-sensors, enigmatic-orphan and orphan nuclear receptors as therapeutic targets in breast-cancer. Oncotarget, 7 (27): 42661-42682. [PMID:26894976]

* Germain P, Staels B, Dacquet C, Spedding M, Laudet V. (2006) Overview of nomenclature of nuclear receptors. Pharmacol Rev, 58 (4): 685-704. [PMID:17132848]

Huang P, Chandra V, Rastinejad F. (2010) Structural overview of the nuclear receptor superfamily: insights into physiology and therapeutics. Annu Rev Physiol, 72: 247-72. [PMID:20148675]

* Safe S, Jin UH, Hedrick E, Reeder A, Lee SO. (2014) Minireview: role of orphan nuclear receptors in cancer and potential as drug targets. Mol Endocrinol, 28 (2): 157-72. [PMID:24295738]

Sladek FM. (2011) What are nuclear receptor ligands?. Mol Cell Endocrinol, 334 (1-2): 3-13. [PMID:20615454]

* Zhi X, Zhou XE, Melcher K, Xu HE. (2016) Structures and regulation of non-X orphan nuclear receptors: A retinoid hypothesis. J Steroid Biochem Mol Biol, 157: 27-40. [PMID:26159912]

1. Benoit G, Cooney A, Giguere V, Ingraham H, Lazar M, Muscat G, Perlmann T, Renaud JP, Schwabe J, Sladek F, Tsai MJ, Laudet V. (2006) International Union of Pharmacology. LXVI. Orphan nuclear receptors. Pharmacol Rev, 58 (4): 798-836. [PMID:17132856]