Deleting Jagged1 in the cranial neural crest (CNC) causes (Wnt1-cre, Jag1 Flox/Flox) mice die at postnatal day 30 due to an inability to masticate, owing to jaw misalignment and poor occlusion, recapitulating the midfacial hypoplasia phenotype of Alagille syndrome [37]. Here, JAG1 is linked to Alagille syndrome.