CDKN2A and familial pancreatic carcinoma: Among many genetic lesions detected in pancreatic cancer, active mutant K-ras is one that occurs in early stages of pancreatic tumorigenesis, followed by inactivation of several tumor suppressors, including p53, p16INK4a, and others (such as SMAD4/DPC4, MLH1, LKB1, PRSS1, and BRCA2) [3, 4].