COX-2 can (1) increase the production of prostaglandins and inhibit the body's immune response, (2) inhibit tumor cell apoptosis and promote cell proliferation, (3) regulate cell cycle progression, (4) promote tumor angiogenesis, (5) increase the expression of matrix metalloproteinases in tumor cells, and (6) induce activation of precursors of carcinogenic substances. Here, PTGS2 is linked to neoplasm.