PTGS2 and neoplasm: The high COX-2 expression revealed a statistically significant correlation with both oral and cutaneous tumours with Ki-67 (r = 0.45; p = 0.03), MI (r = 0.49; p < 0.001), lymphatic invasion (r = 0.41; p = 0.04) and the histological type of tumour (epithelioid and mixed) (r = 0.51; p = 0.003).