Consistent with this possibility, endothelin-3, a gene implicated in Hirschsprung’s disease (Bidaud et al., 1997; Kenny et al., 2000), is important for maintaining a pro-proliferative environment for the vagal neural crest in the avian hindgut (Nagy and Goldstein, 2006) and is required for sacral neural crest colonization in the murine hindgut (Baynash et al., 1994). This evidence concerns the gene EDN3 and Hirschsprung disease.