This finding, already reported by other authors in cancer cell lines with an elevated resistance to apoptosis induced by traditional NSAIDs [27-29] and NO-NSAIDs [30,31], together with the observation that LoVo and LRWZ lines did not express this cyclooxygenase isoform [4], raises intriguing questions about the biological role of COX-2 in the natural history of cancer and also about the mechanisms by which NSAIDs, including NO-NSAIDs, are capable of preventing cancer. The gene discussed is PTGS2; the disease is cancer.