PTGS2 and cancer: Previous studies have reported several mechanisms by which Cox-2 contributes to carcinogenesis as well as cancer progression, including the activation of carcinogens [17], resistance to apoptosis [18,19], immunosuppression [20,21], the promotion of angiogenesis [11,22], the stimulation of proliferation [23] and invasiveness [24], and the autocrine activity of estrogen [25].