PTGS2 and cancer: The present meta-analysis indicated that the expression of COX2 protein in cancer tissues was significantly higher than those in normal and benign tissues (cancer tissues versus normal tissues: OR = 92.86, 95% CI = 53.61~160.84, P < 0.001; cancer tissues versus benign tissues: OR = 11.58, 95% CI = 6.68~20.08, P < 0.001, resp).