It is also possible that the expression of the IL-13Rα1 chain, which associates with the IL-4Rα chain to form a functional receptor, may influence the effects of exogenous IL-4 although MIA PaCa-2 cells as well as the other pancreatic cancer cells lines express IL-13Rα1 (Kornmann et al, 1999a). This evidence concerns the gene IL4 and familial pancreatic carcinoma.