Bergmann et al. (2006) have shown that all (n = 7) pancreatic ductal adenocarcinomas from patients under 40 years-old have overexpression of TGF-β1 and loss or significant reduction of Smad4, which is also known to be a tumor suppressor [98]. This evidence concerns the gene TGFB1 and pancreatic ductal adenocarcinoma.