SMAD4 and pancreatic ductal adenocarcinoma: Pancreatic ductal adenocarcinomas develop as a result of clonally-selected genetic events most commonly involving the genes KRAS, CDKN2A, TP53 and SMAD4 [2-6], less commonly ATM and others [3, 5, 7, 8], and for pancreatic ductal adenocarcinomas arising from intraductal papillary mucinous neoplasms, most commonly KRAS, CDKN2A, TP53, as well as GNAS and RNF43 [9-11].