KRAS and pancreatic intraductal papillary-mucinous neoplasm: Although Kirsten ras oncogen (KRAS) mutations have been identified in nearly all PDAC and precursor lesions—pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and mucinous cystic neoplasm (MCN)—the additional involved signaling pathways make its behavior difficult to predict [2,4,5,6].