APC and desmoid tumor: COX-2 is implicated as a factor in tumor initiation in colonic neoplasia due to mutations in the APC gene [42], and has also been demonstrated to play a role in the growth of desmoid tumors [16], with pharmacologic blockade of COX resulting in decreased cell proliferation in desmoid cell cultures in vitro, and COX-2 blockade resulting in smaller desmoid tumors in an in vivo mouse model.