KRAS and familial pancreatic carcinoma: Common molecular lesions in pancreatic cancer include K-ras-activating mutations and Cyclin Dependent Kinases (CDK) Inhibitor p16INK4A loss of function which are present in the great majority of cases, p53-inactivating mutations that are present in half to three-fourths of patients, and Smad4-(also called DPC4, Deleted in Pancreatic Cancer 4) inactivating mutations that are present in about half of pancreatic cancers [60].