Figure 1D. Copyright: Reprinted with permission from Elsevier from [doi:10.1016/j.ydbio.2005.12.017] Dev Biol 293: 13-24, Chung AC; Xu X; Niederreither KA; Cooney AJ, "Loss of orphan nuclear receptor GCNF function disrupts forebrain development and the establishment of the isthmic organizer." Copyright 2006 [PMID:16530751]