- Orphan nuclear receptor LRH-1 is required to maintain Oct4 expression at the epiblast stage of embryonic development. Gu, P., Goodwin, B., Chung, A.C., Xu, X., Wheeler, D.A., Price, R.R., Galardi, C., Peng, L., Latour, A.M., Koller, B.H., Gossen, J., Kliewer, S.A., Cooney, A.J. Mol. Cell. Biol. (2005)