Nonsteroidal anti-inflammatory drugs (NSAIDs) are antitumorigenic in humans as well as in animal models of intestinal neoplasia, such as the adenomatous polyposis coli Min/ (Apc ) mouse. NSAIDs inhibit cyclooxygenase (COX) isozymes, which are responsible for the committed step in prostaglandin biosynthesis, and this has been considered the primary mechanism by which NSAIDs exert their antitumor...