The pancreas is specified during embryonic development from the gut endoderm. Among the signaling pathways required for the proper development of the organ are the notch and hedgehog signaling pathways. Both of these pathways are reactivated in pancreatic cancers, and sustained hedgehog signaling is required for the viability of most pancreatic cancer cell lines. Further, mouse models of the disease show activation of these pathways, and expression of pancreas progenitor markers. These findings indicate that developmentally regulated gene expression programs are important in the pathogenesis of pancreatic cancer.