SHH and Patent ductus arteriosus: As SHH regulates pancreatic myofibroblast expansion (Collins et al., 2012, Fendrich et al., 2011, Thayer et al., 2003, Tian et al., 2009, Yauch et al., 2008), and ablation of SHH signaling reduces PDA tumor stroma in vivo (Lee et al., 2014, Olive et al., 2009, Rhim et al., 2014), we focused on understanding the trans-cellular signaling consequences of SHH.