SMAD4 and familial pancreatic carcinoma: The activation of the oncogene KRAS2, the deactivation of the tumor suppressor gene (Recombinant Cyclin Dependent Kinase Inhibitor 2A, CDKN2A), the silencing of the tumor suppressor TP53, and the mutation of the pancreatic cancer-related gene 4 (DPC4), which holds a pivotal role in pancreatic carcinogenesis, are all intimately associated with a poor prognosis in patients diagnosed with pancreatic cancer.