They identified commonly mutated genes that characterize pancreatic ductal adenocarcinomas (KRAS, TP53, SMAD4, and CDKN2A) and also identified two additional genes not previously described in human pancreatic ductal adenocarcinomas (KDM6A and PREX) [11-13]. This evidence concerns the gene SMAD4 and pancreatic ductal adenocarcinoma.