Pancreatic cancer is increasingly prevalent and almost uniformly fatal. Studies of the molecular genetics of sporadic and hereditary cases of pancreatic cancer as well as the molecular biology of pancreatic development may advance our understanding of the mechanism underlying pathogenesis of this malignancy. Based on a case of pancreatic adenocarcinoma in a patient with Peutz-Jeghers syndrome (PJS), the clinicopathologic features and molecular genetics of pancreatic tumors associated with this hereditary cancer syndrome are reviewed. Particular emphasis is placed on the developmental roles and biochemical functions of STK11/LKB1, the gene mainly responsible for PJS. Modeling pancreatic cancer in animal models such as the mouse and zebrafish will further our understanding of the pathogenesis of this important disease, and the studies derived from these model organisms can be potentially applied for developing novel preventive and therapeutic strategies.