Table 3.

Transcription Factors Relevant to the Development of Epithelium and Mesenchyme in the Esophagus.

Gene	Expression Pattern	Esophageal Phenotype of Deletion Mutant	Reference
Sox2	Epithelium	Mucous metaplasia in the esophagus and forestomach, and the epithelial stratification is disrupted.	(Que et al., 2007)
P63	Epithelium	Mucous metaplasia in the esophagus and forestomach, and the epithelial stratification is disrupted.	(Daniely et al., 2004; Wang et al., 2011)
Keap1	Epithelium	Thickened cornification (keratin layer) in the esophagus and forestomach.	(Wakabayashi et al., 2003)
Foxp1/Foxp2	Foxp1 (epithelium and mesenchyme); Foxp2 (mesenchyme)	Foxp1+/−; Foxp2−/− mutants have a complete absence of esophageal skeletal muscle.	(Shu et al., 2007)
HoxC4	Mesenchyme	Disorganized musculature. Complete esophageal blockage due to epithelial proliferation.	(Boulet and Capecchi, 1996)