MUC4 and familial pancreatic carcinoma: To investigate the role of MUC4/Y in pancreatic cancer, PANC-1 cells, which do not express endogenous MUC4 [22], were infected with viral supernatant containing either MUC4/Y or empty lentiviral expression plasmids for effective MUC4/Y overexpression or to serve as controls, respectively.