PTGS2 and breast cancer: The chemo preventive activity of NSAIDs against breast cancer provides the first evidence that cyclooxygenase-2 blocking agent, celecoxib-α specific COX-2 inhibitor suppressed the incidence, multiplicity, and size of malignant breast tumors, possesses strong chemopreventive activity against mammary carcinogenesis (Harris et al., 2000[9]).