To that end, as TGF-β is a known mediator of tumor progression/EMT and immune regulation [68], we addressed the following general questions: first, does TGF-β regulate B7-1 expression in pancreatic cancer cell lines; and if so, second, would B7-1 have a critical role in TGF-β stimulated cell migration/invasion and the induction of genes critical to EMT development? This evidence concerns the gene CD80 and familial pancreatic carcinoma.