Whereas the developing and normal adult pancreas lack expression of Hh pathway ligands, the Sonic Hedgehog (SHH) and Indian Hedgehog (IHH) ligands are prominently induced in the pancreatic epithelium upon injury and throughout PDA development, from early precursor pancreatic intraepithelial neoplasia (PanIN) to invasive disease (Berman et al., 2003; Thayer et al., 2003; Prasad et al., 2005; Nolan-Stevaux et al., 2009). This evidence concerns the gene SHH and Patent ductus arteriosus.