GRHL3 and van der Woude syndrome: Irf6 has been suggested to activate Grhl3 in the zebrafish periderm (de la Garza et al., 2013) and mutations in Irf6 or Grhl3 are associated with neural crest defects (cleft-lip/palate) characteristic of Van der Woude syndrome (Peyrard-Janvid et al., 2014).