SMAD4 and neoplasm: To gain insight into the functional role of SMAD4 loss in PDAC cells, we first selected two SMAD4-deficient PDAC cell lines (AsPC-1 and CFPAC-1) and SMAD4 wild-type PANC-1 cells as the model cell lines in which to study the anti-tumor effects of SMAD4 in human PDAC.