Thus, despite the fact that PTEN inactivation through PTEN mutation or deletion is infrequent in pancreatic cancer, we raise the hypothesis that TGF-β1 overexpression may lead to reduced PTEN mRNA levels in pancreatic cancers which may give these cells an additional growth advantage and, thus, contributes to the aggressive phenotype of this cancer. This evidence concerns the gene TGFB1 and familial pancreatic carcinoma.