Epidemiological, clinical, and preclinical studies have shown that the inhibition of PGE2 synthesis through the use of either nonsteroidal anti-inflammatory drugs (NSAIDs) or specific COX-2 inhibitors has the potential to reduce the risk of developing certain cancers, including breast, head and neck squamous cell carcinoma, osteosarcoma, pancreas, and prostate cancers, and to reduce the mortality caused by these cancers [28–35]. Here, PTGS2 is linked to cancer.