Prior to gastrulation, SOX2 is expressed throughout the epiblast (inferred from mouse embryos). During gastrulation, SOX2 becomes restricted to the anterior epiblast that develop into the anterior neural plate and the anterior part of posterior neural plate and persists in the neural tube (inferred from mouse embryos). SOX2 is activated by the N1 enhancer in the posterior part of the posterior neural plate and by the N2 enhancer in the anterior neural plate. WNT3A signaling and FGF8 signaling originating from the hordoneural hinge activate the N1 enhancer, a conserved 420 bp sequence located downstream of the SOX2 coding region (inferred from mouse homologs). As the node migrates posteriorly, other uncharacterized factors are believed to maintain SOX2 expression in the posterior neural plate.