COX-2 protein, also known as Cyclooxygenase-2 or PGHS-2, is a member of the cyclooxygenase superfamily. This recombinant protein plays a specific enzymatic role in the biological system, converting arachidonic acid (AA) into prostaglandin G2 and other peroxide substances, participating in the biosynthesis of prostaglandins. Under normal physiological conditions, most tissue cells do not express COX-2 protein. However, in pathological states such as inflammation and tumorigenesis, COX-2 protein expression is upregulated in response to proinflammatory mediators, including inflammatory stimuli, damage, mitogens, and carcinogens. This process involves the release of arachidonic acid from cell membrane phospholipids through the phospholipase A2 pathway, followed by the synthesis of inflammatory mediators such as prostaglandin E2 (PGE2) catalyzed by COX-2, participating in various physiological and pathological processes in the body. Moreover, the enzymatic activity of COX-2 protein is not limited to arachidonic acid. It can also act on dihomo-γ-linolenic acid (DGLA) and eicosapentaenoic acid (EPA), generating PGH1 and PGH3 as precursors of different series of prostaglandins.