KRAS and pancreatic ductal adenocarcinoma: The most commonly diagnosed type of pancreatic cancer is pancreatic ductal adenocarcinoma (PDAC), which arises from exocrine alteration of the pancreatic epithelium, and over 90% of PDAC patients exhibit a mutation of Kirsten rat sarcoma viral oncogene homolog (KRAS), which is a Ras family GTPase that activates phosphoinositide-3 kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways.