This cluster of papers focuses on the use of cyclooxygenase-2 (COX-2) inhibitors, such as rofecoxib, celecoxib, and naproxen, in the context of inflammation and cancer. It explores the gastrointestinal and cardiovascular toxicity, chemopreventive effects, and potential risks associated with these drugs. The cluster also delves into the molecular biology of prostaglandins, particularly prostaglandin E2, and their role in modulating immune responses and promoting cancer growth.