POU5F1 (OCT4), SOX2, and NANOG bind the promoter of the ZIC3 gene (Boyer et al. 2005, Lister et al. 2009) and POU5F1 (Babaie et al. 2007, Greber et al. 2007) and SOX2 (Greber et al. 2007) activate expression. In mouse, Zic3 binds the Nanog promoter and activates transcription, thus forming a positive feedback loop (Lim et al. 2010).