The role of COX-2 has been previously studied in colorectal cancer, and shown to be expressed in adenomas and carcinomas (Eberhart et al, 1994; Kargman et al, 1995; Sano et al, 1995; Dimberg et al, 1999; Cianchi et al, 2001; Denkert et al, 2001). Here, PTGS2 is linked to colorectal cancer.