PTGS2 and neoplasm: In a study using prostate-specific phosphatase and tensin homolog (Pten)−/− mice, we found that an HFD doubled the tumor weight in the model mice but did not increase tumor weight in mice administrated celecoxib, a cyclooxygenase-2 (COX-2) inhibitor, or an anti-interleukin (IL)-6 antibody [29].