The observed association is also consistent with experimental evidence indicating that chemopreventive effects of aspirin and other NSAIDs could be mediated through the inhibition of COX-2 enzyme, which appears to be overexpressed in human lung carcinoma, particularly in non-small cell lung cancer (Hida et al, 1998; Wolff et al, 1998; Ochiai et al, 1999). Here, PTGS2 is linked to lung carcinoma.