PDX1 and Patent ductus arteriosus: To dissect the molecular mechanisms of enhancer activation/inactivation during PDA metastasis, we developed 3D organoid culture using PDA cells collected from the primary tumors and matched metastatic lesions derived from the Kras+/LSL-G12D; Trp53+/LSL-R172H; Pdx1-Cre (KPC) PDA mouse model [36].