PTGS2 and cancer: We suggest that the anti-inflammatory effect of aspirin is exerted via inhibition of COX enzymes.48 DNA-damaging agents such as doxorubicin are known to induce expression of COX-2, in association with p53.79 The anti-cancer effects of our combinatorial treatment regime appear to be mediated by both COX-dependent and COX-independent pathways, as evident by reduction of COX-2 expression after combinatorial DA treatment.