As aspirin, a nonselective COX inhibitor, reduces the risk of oesophageal cancer (Thun et al, 1993; Funkhouser and Sharp, 1995) and as specific COX-2 inhibitors suppress tumorigenesis both in experimental tumour models (Kawamori et al, 1998; Harris et al, 2000; Buttar et al, 2002; Thun et al, 2002; Zweifel et al, 2002) and in diseases such as human familial adenomatous polyposis (Steinbach et al, 2000), prospective clinical studies are needed to evaluate the chemopreventive potential of COX-2 inhibitors. The gene discussed is PTGS2; the disease is Familial adenomatous polyposis.