Although the present study establishes that a reduction in the K-ras 4A/4B ratio does not affect Apc-driven intestinal tumorigenesis per se the finding that the ratio is reduced in Min adenomas that lack K-ras activating mutations raises the intriguing possibility that K-ras may have a more widespread role in tumorigenesis in addition to that in lung, colon and pancreatic cancers that normally harbour K-ras activating mutations [reviewed [6]]. This evidence concerns the gene APC and pancreatic neoplasm.