SMAD4 and pancreatic adenocarcinoma: Pancreatic adenocarcinomas display a characteristic profile of genetic lesions, consisting of mutations in INK4A, KRAS, SMAD4/DPC4, and TP53 in a high proportion of tumors, and less frequent mutations in LKB1, APC, CTNNB1, ATM, BRCA2, ACVR1B, MKK4 (Ras downstream effector), and ARID1A [8,9].