When transgenic mice that express the human carcinoembryonic antigen (CEA) gene (CEA transgenic) were bred with mice bearing a mutation in the Apc(Delta850) gene (multiple intestinal neoplasia mice), the progeny (CEA transgenic/multiple intestinal neoplasia) spontaneously develop multiple intestinal neoplasms that overexpress CEA and COX-2.
Cyclooxygenase-2 is thought to play a role in the development of intestinal tumors and levels are elevated in approximately 80 to 90 percent of human colorectal carcinomas.